user25701: I'm fairly new to chess (~3 months) and I have almost entirely been playing on chess.com where my rating sits somewhere between 1000 and 1100. Recently, I decided to sign up for lichess.org, where I was placed at ~1650 as I haven't played many games yet, and unsurprisingly I lose quite often.
But facing higher rated players made me realise I don't know how to win a game of chess.
On chess.com, the people I face will almost always trade pieces if offered, so if I have a material advantage it is very easy to trade off all other pieces then staircase checkmate and win. Facing higher rated players on lichess made me realise that if they don't cooperate like this I have no idea what to do. I know I sound pretty stupid here but somehow I have just never had a game like this before.
In this game, by the end Stockfish says it was -3.1 (I played the black pieces) when my opponent lost on time, but if they didn't, I have no idea how I was going to win if they didn't at least trade queens.
[Event "Rated Rapid game"]
[FEN ""]
[StartFlipped "1"]
[Date "2020.12.13"]
[White ""]
[Black "Me"]
[Result "0-1"]
[UTCDate "2020.12.13"]
[UTCTime "08:02:31"]
[WhiteElo "1655"]
[BlackElo "1645"]
[WhiteRatingDiff "-6"]
[BlackRatingDiff "+10"]
[Variant "Standard"]
[TimeControl "600+5"]
[ECO "C48"]
[Opening "Four Knights Game: Spanish Variation, Classical Variation"]
[Termination "Time forfeit"]

1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bc5 5. O-O a6 6. Ba4 b5 7. Bb3 O-O 8. a3 Bb7 9. Re1 Ng4 10. Rf1 Nd4 11. Ba2 Nxf3+ 12. Qxf3 Qh4 13. h3 Nf6 14. b4 Bd4 15. Bb2 Bxe4 16. Qe2 Bxc3 17. Bxc3 Qg5 18. f3 Bxc2 19. d4 Qg6 20. dxe5 Bd3 21. Qb2 Bxf1 22. Rxf1 Ne8 23. f4 Qb6+ 24. Bd4 Qc6 25. Rc1 Qh6 26. Be3 d6 27. exd6 Nxd6 28. Rxc7 Rac8 29. Ra7 Ra8 30. Qf2 Rxa7 31. Bxa7 Qf6 32. Bd4 Qh6 33. f5 Qc1+ 34. Kh2 Nc4 0-1

So I'm not really looking for somebody to tell me the best continuation of this game so I could win, but is this a problem with playing too passively? As in, "I should be actively attacking the king more" is my assumption, but I'm unsure how to learn about how to do that. I came across Vukovic's Art of Attack in Chess when searching online but according to the /r/chess wiki that book is for 1800-2000 rated players. So my question is what should I be focusing on to be able to win in these positions?

user-1: My apologies in advance for the length of the answer. Additionally, I understand that the answer isn't responding directly to the question. Some parts of the answer are much more specific than what was asked in the question, and I've written analysis about a particular position from the game, even though the question specifically asks not to. The analysis is also probably complex enough that it would be hard to do in a rapid game. In my defense, I fully believe that the answer is the most helpful I can give. The game in the original post is quite interesting, and there are a number of complicated positions in the game, so a simple analysis won't cut it. Further, there just isn't enough good, specific information out there on the subject of playing with a material advantage--I felt the necessity to give something.
I will put a summary of my post here, though: treat the material advantage as one of many positional aspects that guide you.

Firstly, congratulations on playing a very good game (especially for a fairly new player) and then accurately identifying what areas could have been improved--that's a wonderful skill to have. As for your question, my experience working with relatively new players has made me quite skeptical that giving the "standard" advice for playing in winning positions is helpful. Just to be clear, the "standard" advice is completely correct, and  a quick summary of it is:

trade pieces and simplify
attack the king instead of playing passively
watch out for counterplay

Why am I skeptical that these guidelines are helpful? First, the advice is contradictory (trading defeats the purpose of playing for an attack, and attacking and defending against counterplay are hard to reconcile). However, the more important reason is that the real problem for the majority of players is that they find it difficult to play without clear positional advantages. (The reason that this is confused for not knowing how to play with a material advantage is because positional advantages won't be given up for nothing--usually, this happens after a tactical sequence that wins material.) For instance, consider the position just after you win the Exchange:
[White "NN"]
[Black "Matt"]
[FEN "r4rk1/2pp1ppp/p4nq1/1p2P3/1P6/P1B2P1P/BQ4P1/5RK1 b - - 0 22"]

What can we say about the position?

Black is up an Exchange and a pawn
White has a strong bishop pair and has a clear plan of advancing the kingside pawns (that is, the e-pawn and f-pawn)
Black's queen might be vulnerable, the rooks lack good files, the knight has no outpost, and Black has no central presence; it's difficult to find a way to put the pieces on good squares

In short, White has serious compensation for the material. Black is definitely better, but I would not call the position "won." You did play a bit passively from this position, but passivity is usually a problem with moves, and not with thought process. There are players that just habitually play passively, but I'd definitely need to see more of your games to judge that, and judging from your play earlier in the game, I don't think you do. From moves 9 to 15, for instance, you play a series of positionally strong active moves designed to pressure the kingside and then the e4 pawn.
It seems to me that the problem isn't with activity or passivity, but rather that in the diagram position above, it's difficult to come up with a good positional plan. In the early middlegame, being able to "feel" good squares for your pieces helped you come up with good moves like ...Qh4 and ...Bd4, but it's hard to know where to put your pieces in positions like the one above. Thus, you made a few moves without a plan (like moving your queen along the 6th rank).
How can we improve our play in these positions? The basic skill that helps us here is learning how to make positional advantages appear. I'm aware that you're not looking for specific advice on how to play this position, but it's quite difficult to teach this sort of thing without a specific example, so I'll just write down my thought process. The generally applicable idea is that you need to synthesize your calculations with general positional knowledge, just like in any other chess position. This is where the "standard" advice I mentioned at the beginning becomes relevant: it's part of your positional knowledge of positions where one side has a material advantage. In your particular position, the emphasis should be on stopping the opponent from gaining counterplay, since that's what he's about to do.
The particular "sticking point" that's difficult for a lot of players to learn is that you need to make certain features appear in the position, instead of just exploiting them when they do. How do we do this? Let's look at a sample thought process:

Obviously, the first priority is finding a good square for the knight. The only two safe squares are e8 and h5, and neither of them are long-term homes for the knight--we need to make one! Looking ahead a bit, I see three ideas: ...Nh5-g3-f5, ...Ne8 followed by ...c6 and ...Nc7-d5, and ...Ne8 followed by ...d6, hoping for exd6, and ...Nxd6-c4. Each of these has its drawbacks: ...Nf5 can be pushed out with g4 or pinned with Bb1, the ...c6 plan looks a bit artificial (read: dumb), and it seems hard to force him to play exd6.
The rooks need open files. We have to make them! Some ways to open files in this position are ...d6, ...f6, and ...a5.

Note how none of these observations rely on the fact that you're up material! The next step is to start calculating. I'd start with ...Nh5, because if it works it will effectively freeze his kingside attack, and if White has no counterplay Black will eventually win. (This is where we use the fact that you're up material--part of the "standard" advice is that limiting counterplay is good when you're up material.) My two main worries were that the knight won't be able to stay on f5 because of g4 and Bb1. Do these work?
[Event "Rated Rapid game"]
[Site "?"]
[Date "2020.12.13"]
[Round "?"]
[White "NN"]
[Black "Matt"]
[Result "0-1"]
[FEN ""]
[StartFlipped "1"]
[UTCDate "2020.12.13"]
[UTCTime "08:02:31"]
[WhiteElo "1655"]
[BlackElo "1645"]
[WhiteRatingDiff "-6"]
[BlackRatingDiff "+10"]
[Variant "Standard"]
[TimeControl "600+5"]
[ECO "C48"]
[Opening "Four Knights Game: Spanish Variation, Classical Variation"]
[Termination "Time forfeit"]

1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bc5 5. O-O a6 6. Ba4 b5 7. Bb3 O-O 8. a3 Bb7 9. Re1 Ng4 10. Rf1 Nd4 
11. Ba2 Nxf3+ 12. Qxf3 Qh4 13. h3 Nf6 14. b4 Bd4 15. Bb2 Bxe4 16. Qe2 Bxc3 17. Bxc3 Qg5 18. f3 Bxc2 19. d4 Qg6 20. dxe5 Bd3 
21. Qb2 Bxf1 22. Rxf1 Nh5! 23. f4 Ng3 24. Bb1! {This is tricky. We have to move the queen, and
this complicates the ...Nf5 idea.} (24. Rf3 Nf5 25. Kh1 (25. g4? h5! 26. g5 d6 {
I stopped calculating here. The knight is fixed on f5, and the center will be
opened for the rooks.}) 25... h5! {I stopped calculating here, because White
won't be able to force g4. The next moves will be ...Rad8, ...d6, ...Rfe8 in
some order, opening files for the rooks.}) 24... Qc6! {This is probably the
most difficult move to see. Having realized that ...Nf5 probably isn't going
to happen, let's try putting the knight on e4. It turns out that we're just in
time to make this work.} (24... Qe6?! 25. Rf3 Nf5 26. Qf2! {The idea is to play
g4 without worrying about ...Nh4. I stopped calculating here because I can't
stop g4 and White's pawns look very strong. My computer says this position is
good for Black, but I wouldn't like to play it.}) (24... Qh5?? 25. Rf3 Nf5 26. g4
{I lose the knight.}) 25. Rf3 Ne4 26. Bxe4 (26. Qc2 f5! {Now either my knight gets a permanent outpost or White is forced to open
files for the rook.} 27. exf6 Nxf6 28. Bxf6 Qxc2 {I stopped calculating here.
White can't force a capture on h7, so I have nothing to worry about.}) 26...
Qxe4 {I made a piece trade (more "standard" knowledge) and now White's attack
looks weak.} 27. e6 f6 28. exd7 Rad8 {I stopped calculating here, since I will
win the pawn and there is no danger to my position.} *

This is not to say that my analysis is perfect--the computer objects to various things I've said here, the most glaring of which is that it's actually quite tricky to deal with 26. Bd4. The only purpose of the answer is to give an example of a human thought process in a very complicated position with material advantage, and to emphasize that the material advantage doesn't dominate the analysis--it is just blended in with the other positional features.

user14340: First consider the difference between a 'truly' won position vs a 'theoretically winning' position. By that I mean - a position that is within your own abilities to convert to a win, in a way you can already see, vs a position that seems like it 'should be winning'. You see that stockfish says the position was -3.1, but at your rating level, -3.1 isn't 'truly' won -  first of course because you point out that you can't see how to convert it, and second simply because at your current level, it would be very natural to overlook a tactic that you or your opponent could perform with a larger impact than a 3 point material swing.
So move away from calling a position like this 'won'; it could lead you to let your guard down. At the same time, a 3 point advantage 'should' be enough to convert to a win with perfect play, in most cases.
So what gets in the way of you converting this 'theoretically winning' position to a 'truly won' position? Complexity. Particularly at your level of play, but really in all levels of chess, complexity and asymmetry is an advantage to the player on the backfoot.
Imagine an endgame where you have a rook and nothing else, and I just have a king. This should be a 100% won game (and if you don't consider that completely won, work on your endgames, so that you can convert a win in any circumstance where your opponent has only a bare king, and you have a minimum of material). Now now add 2 pawns and a knight for each of us to the board. Where before you would be able to easily slide your rook away from my king and make the mechanical advance that leads to checkmate, now you need to be cautious - are my pawns able to make a break for the 8th rank? Can my knight fork your rook and king? Is your knight trapped by the position of your own pieces? **Complexity has created the opportunity for you to make a mistake, and the same "5 point material advantage" of an extra rook is not so straightforward to convert to a win.
So reduce the complexity. Trade everything down until you have a rook and I have nothing. You indicate this is what you're trying to do, but that your trades are 'refused'. You will need to become better at 'forcing' trades. If you fork my knight and king with your knight, and your knight is protected, you have forced me to take your knight. Simply moving your knight in view of mine to 'tempt' me to take it requires me to choose to do so - as you rise in your chess level, your opponents will more often have their own plans, and you should never rely on someone 'being bad enough that they will play the way I want', always try to play in a way that doesn't require mistakes on the part of your opponent.
And reduce the asymmetry. Imagine you have a rook and 2 pawns, and I have a rook. Because we both have the same major piece, I can't attack your rook in a way that your rook can't attack back. Tactics might be possible on my part (skewering your king with your rook behind, as an example), but mostly your position is similar (but better) than mine. Asymmetry creates complexity that allows tactics to develop. Imagine instead I have a bishop and 2 pawns, and you have a rook and 2 pawns. From a material standpoint, this is still you being 'two pawns-worth of material' ahead, but now my bishop can attack your rook in a way that you can't immediately attack back, and my bishop also defends my pawns differently - it can become part of the pawn chain if needed, etc. Asymmetry naturally creates complexity, which creates the opportunity for me to prepare tactics, and also makes it easier for you to overlook something on the board.
So your goal when it looks like you have enough material advantage to convert to a win (as mentioned in other answers, the way to know this is to practice your endgames - for example are you confident in your ability to checkmate with a bishop and knight only?) would be as the mid-game winds down, to:
(1) Play defensively. Keep your pieces connected and close to eachother. Being aggressive can be risky, and you no longer need risk to win, you need simplicity. Don't overlook your opponent's threats, deal with them, even if it seems slower than a 'near checkmate' that you can't quite calculate but you think is probably there. Keep in mind that for a sub ~1600 rated player, the most immediate improvement to your play will likely be just to not 'drop' / 'hang' pieces. Simply by defending all your pieces, you will be doing something that your opponents are not always doing.
(2) Simplify. Force trades of material. Reduce asymmetry.
(3) Watch for potential pawn breaks, on your side and the opponents. 2 connected pawns on the 6th rank are worth about as much as a rook, so don't ignore the threat of promotion, even if you feel you have a material advantage.
(4) Keep your opponent's king "out of the game", by pushing it into a corner, especially preventing it from approaching your opponent's connected pawns. A king next to 2 pawns on the 6th rank is quite frightening indeed.
(5) When safe bring your own king into the game. As the material on the board simplifies, the relative power of a king increases, especially if there are no queens on the board, and even more so if there are no rooks on the board. If you're '2 points of material' ahead, but your opponent uses their king and you don't use yours, you will be unlikely to convert to a win.
(6) Checkmate using simple principles once the dust has settled. Really learn your endgames so that you are confident in all simplistic checkmates (especially with a single rook, and a single pawn - sometimes a single pawn is winning, sometimes it is a draw, you absolutely must learn how to win with a single pawn, because that's how a 1 point material advantage converts to a win).

user15223: I remember reading about this from one of GM Yasser Seirawan's books. What you want to do is:

Pick a target
Figure out how to attack it

In this case the obvious target is the White pawn on a3. Why this pawn? Because it cannot move (a4 bxa4 wins the pawn). It stands to reason it's easier to attack something that cannot move. The a3-pawn is also not easy to defend - it can no longer be defended by a pawn, so it must be defended by pieces, and you have more powerful pieces.
Your last move 34...Nc4 accomplishes this goal of hitting the pawn. White can't defend it anymore. Next turn, you play 35...Nxa3 which increases your material advantage, and now you pick a new target - this time the pawn on b4. The reason is the same, it cannot move and it cannot be defended by a White pawn. Once you have identified the target it becomes easy to plan how to take it: you play ...Rc4, ...Nc6, ...Qb1, etc, and then you will have more attackers than White has defenders. After you grab the b4-pawn you have powerful connected passed pawns that you can shepherd to promotion & victory.
Note this analysis is superficial - 35.a4 bxa4?? actually loses you most of your advantage according to Stockfish - but that is because of the specifics of the position (in this case, White's bishops are actually quite threatening to your King).
One more thing: because you are ahead in material, another powerful plan is to force trades. Your opponent will be trying their darnedest not to acquiesce, but a material advantage lets you create threats that your opponent cannot parry. In the final position for example, an immediate threat you have is ...Qd2. If opponent does not trade queens, you take the bishop on a2. If White plays 35.Qg3 for example, then ...Qc2 traps the bishop and forces another trade (of course, you will have to defend against the threatened Qxg7# first).

user4418: There are two key things you need to do.
The first is to know how to win a won endgame. You do that by studying endgames. That will do two important things for you. Apart from teaching you how to win a won endgame, it will also teach you to recognise which endgame positions are won, and which are drawn, despite your material advantage. That way when you are in a winning middlegame you know what kind of endgame you are aiming for.
The second really important thing to do is to keep on fighting. The aim is not to get a winning middlegame position, it is to win the game. To that end a winning middlegame position is just one stop on the way to your real desired destination.
If you are driving to visit friends or family and you stop two thirds of the way there for petrol (or gas if you live in the US) you don't stop because you think you have arrived. You carry on after the stop, in just the same way as you did before the stop, except that you are no longer worried that you are going to run out of fuel (or not win the game).
This tendency to sit back once you have a theoretically winning position is something which affects all players. You have to fight it by trying even harder to not let your opponent back into the game and to win it yourself. Perhaps one good way of doing this is by starting each think about your next move by asking yourself "Why did my opponent do that? What are they trying to do? How can I stop them?"

25701: <p>I'm fairly new to chess (~3 months) and I have almost entirely been playing on chess.com where my rating sits somewhere between 1000 and 1100. Recently, I decided to sign up for lichess.org, where I was placed at ~1650 as I haven't played many games yet, and unsurprisingly I lose quite often.</p>
<p>But facing higher rated players made me realise I don't know how to win a game of chess.</p>
<p>On chess.com, the people I face will almost always trade pieces if offered, so if I have a material advantage it is very easy to trade off all other pieces then staircase checkmate and win. Facing higher rated players on lichess made me realise that if they don't cooperate like this I have no idea what to do. I know I sound pretty stupid here but somehow I have just never had a game like this before.</p>
<p>In this game, by the end Stockfish says it was -3.1 (I played the black pieces) when my opponent lost on time, but if they didn't, I have no idea how I was going to win if they didn't at least trade queens.</p>
<pre><code>[Event &quot;Rated Rapid game&quot;]
[FEN &quot;&quot;]
[StartFlipped &quot;1&quot;]
[Date &quot;2020.12.13&quot;]
[White &quot;&quot;]
[Black &quot;Me&quot;]
[Result &quot;0-1&quot;]
[UTCDate &quot;2020.12.13&quot;]
[UTCTime &quot;08:02:31&quot;]
[WhiteElo &quot;1655&quot;]
[BlackElo &quot;1645&quot;]
[WhiteRatingDiff &quot;-6&quot;]
[BlackRatingDiff &quot;+10&quot;]
[Variant &quot;Standard&quot;]
[TimeControl &quot;600+5&quot;]
[ECO &quot;C48&quot;]
[Opening &quot;Four Knights Game: Spanish Variation, Classical Variation&quot;]
[Termination &quot;Time forfeit&quot;]

1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bc5 5. O-O a6 6. Ba4 b5 7. Bb3 O-O 8. a3 Bb7 9. Re1 Ng4 10. Rf1 Nd4 11. Ba2 Nxf3+ 12. Qxf3 Qh4 13. h3 Nf6 14. b4 Bd4 15. Bb2 Bxe4 16. Qe2 Bxc3 17. Bxc3 Qg5 18. f3 Bxc2 19. d4 Qg6 20. dxe5 Bd3 21. Qb2 Bxf1 22. Rxf1 Ne8 23. f4 Qb6+ 24. Bd4 Qc6 25. Rc1 Qh6 26. Be3 d6 27. exd6 Nxd6 28. Rxc7 Rac8 29. Ra7 Ra8 30. Qf2 Rxa7 31. Bxa7 Qf6 32. Bd4 Qh6 33. f5 Qc1+ 34. Kh2 Nc4 0-1
</code></pre>
<p>So I'm not really looking for somebody to tell me the best continuation of this game so I could win, but is this a problem with playing too passively? As in, &quot;I should be actively attacking the king more&quot; is my assumption, but I'm unsure how to learn about how to do that. I came across Vukovic's <em>Art of Attack in Chess</em> when searching online but according to the /r/chess wiki that book is for 1800-2000 rated players. So my question is what should I be focusing on to be able to win in these positions?</p>
 -1: <p>My apologies in advance for the length of the answer. Additionally, I understand that the answer isn't responding directly to the question. Some parts of the answer are much more specific than what was asked in the question, and I've written analysis about a particular position from the game, even though the question specifically asks not to. The analysis is also probably complex enough that it would be hard to do in a rapid game. In my defense, I fully believe that the answer is the most helpful I can give. The game in the original post is quite interesting, and there are a number of complicated positions in the game, so a simple analysis won't cut it. Further, there just isn't enough good, specific information out there on the subject of playing with a material advantage--I felt the necessity to give something.</p>
<p>I will put a summary of my post here, though: <strong>treat the material advantage as one of many positional aspects that guide you</strong>.</p>
<hr />
<p>Firstly, congratulations on playing a very good game (especially for a fairly new player) and then accurately identifying what areas could have been improved--that's a wonderful skill to have. As for your question, my experience working with relatively new players has made me quite skeptical that giving the &quot;standard&quot; advice for playing in winning positions is helpful. Just to be clear, the &quot;standard&quot; advice is completely correct, and  a quick summary of it is:</p>
<ul>
<li>trade pieces and simplify</li>
<li>attack the king instead of playing passively</li>
<li>watch out for counterplay</li>
</ul>
<p>Why am I skeptical that these guidelines are helpful? First, the advice is contradictory (trading defeats the purpose of playing for an attack, and attacking and defending against counterplay are hard to reconcile). However, the more important reason is that the real problem for the majority of players is that they find it difficult to play without clear positional advantages. (The reason that this is confused for not knowing how to play with a material advantage is because positional advantages won't be given up for nothing--usually, this happens after a tactical sequence that wins material.) For instance, consider the position just after you win the Exchange:</p>
<pre><code>[White &quot;NN&quot;]
[Black &quot;Matt&quot;]
[FEN &quot;r4rk1/2pp1ppp/p4nq1/1p2P3/1P6/P1B2P1P/BQ4P1/5RK1 b - - 0 22&quot;]
</code></pre>
<p>What can we say about the position?</p>
<ul>
<li>Black is up an Exchange and a pawn</li>
<li>White has a strong bishop pair and has a clear plan of advancing the kingside pawns (that is, the e-pawn and f-pawn)</li>
<li>Black's queen might be vulnerable, the rooks lack good files, the knight has no outpost, and Black has no central presence; it's difficult to find a way to put the pieces on good squares</li>
</ul>
<p>In short, White has serious compensation for the material. Black is definitely better, but I would not call the position &quot;won.&quot; You did play a bit passively from this position, but passivity is usually a problem with moves, and not with thought process. There are players that just habitually play passively, but I'd definitely need to see more of your games to judge that, and judging from your play earlier in the game, I don't think you do. From moves 9 to 15, for instance, you play a series of positionally strong active moves designed to pressure the kingside and then the e4 pawn.</p>
<p>It seems to me that the problem isn't with activity or passivity, but rather that in the diagram position above, it's difficult to come up with a good positional plan. In the early middlegame, being able to &quot;feel&quot; good squares for your pieces helped you come up with good moves like ...Qh4 and ...Bd4, but it's hard to know where to put your pieces in positions like the one above. Thus, you made a few moves without a plan (like moving your queen along the 6th rank).</p>
<p>How can we improve our play in these positions? The basic skill that helps us here is learning how to <em>make positional advantages appear</em>. I'm aware that you're not looking for specific advice on how to play this position, but it's quite difficult to teach this sort of thing without a specific example, so I'll just write down my thought process. The generally applicable idea is that <strong>you need to synthesize your calculations with general positional knowledge, just like in any other chess position</strong>. This is where the &quot;standard&quot; advice I mentioned at the beginning becomes relevant: it's part of your positional knowledge of positions where one side has a material advantage. In your particular position, the emphasis should be on stopping the opponent from gaining counterplay, since that's what he's about to do.</p>
<p>The particular &quot;sticking point&quot; that's difficult for a lot of players to learn is that <strong>you need to make certain features appear in the position, instead of just exploiting them when they do</strong>. How do we do this? Let's look at a sample thought process:</p>
<ul>
<li>Obviously, the first priority is finding a good square for the knight. The only two safe squares are e8 and h5, and neither of them are long-term homes for the knight--we need to make one! Looking ahead a bit, I see three ideas: ...Nh5-g3-f5, ...Ne8 followed by ...c6 and ...Nc7-d5, and ...Ne8 followed by ...d6, hoping for exd6, and ...Nxd6-c4. Each of these has its drawbacks: ...Nf5 can be pushed out with g4 or pinned with Bb1, the ...c6 plan looks a bit artificial (read: dumb), and it seems hard to force him to play exd6.</li>
<li>The rooks need open files. We have to make them! Some ways to open files in this position are ...d6, ...f6, and ...a5.</li>
</ul>
<p>Note how none of these observations rely on the fact that you're up material! The next step is to start calculating. I'd start with ...Nh5, because if it works it will effectively freeze his kingside attack, and if White has no counterplay Black will eventually win. (This is where we use the fact that you're up material--part of the &quot;standard&quot; advice is that limiting counterplay is good when you're up material.) My two main worries were that the knight won't be able to stay on f5 because of g4 and Bb1. Do these work?</p>
<pre><code>[Event &quot;Rated Rapid game&quot;]
[Site &quot;?&quot;]
[Date &quot;2020.12.13&quot;]
[Round &quot;?&quot;]
[White &quot;NN&quot;]
[Black &quot;Matt&quot;]
[Result &quot;0-1&quot;]
[FEN &quot;&quot;]
[StartFlipped &quot;1&quot;]
[UTCDate &quot;2020.12.13&quot;]
[UTCTime &quot;08:02:31&quot;]
[WhiteElo &quot;1655&quot;]
[BlackElo &quot;1645&quot;]
[WhiteRatingDiff &quot;-6&quot;]
[BlackRatingDiff &quot;+10&quot;]
[Variant &quot;Standard&quot;]
[TimeControl &quot;600+5&quot;]
[ECO &quot;C48&quot;]
[Opening &quot;Four Knights Game: Spanish Variation, Classical Variation&quot;]
[Termination &quot;Time forfeit&quot;]

1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bc5 5. O-O a6 6. Ba4 b5 7. Bb3 O-O 8. a3 Bb7 9. Re1 Ng4 10. Rf1 Nd4 
11. Ba2 Nxf3+ 12. Qxf3 Qh4 13. h3 Nf6 14. b4 Bd4 15. Bb2 Bxe4 16. Qe2 Bxc3 17. Bxc3 Qg5 18. f3 Bxc2 19. d4 Qg6 20. dxe5 Bd3 
21. Qb2 Bxf1 22. Rxf1 Nh5! 23. f4 Ng3 24. Bb1! {This is tricky. We have to move the queen, and
this complicates the ...Nf5 idea.} (24. Rf3 Nf5 25. Kh1 (25. g4? h5! 26. g5 d6 {
I stopped calculating here. The knight is fixed on f5, and the center will be
opened for the rooks.}) 25... h5! {I stopped calculating here, because White
won't be able to force g4. The next moves will be ...Rad8, ...d6, ...Rfe8 in
some order, opening files for the rooks.}) 24... Qc6! {This is probably the
most difficult move to see. Having realized that ...Nf5 probably isn't going
to happen, let's try putting the knight on e4. It turns out that we're just in
time to make this work.} (24... Qe6?! 25. Rf3 Nf5 26. Qf2! {The idea is to play
g4 without worrying about ...Nh4. I stopped calculating here because I can't
stop g4 and White's pawns look very strong. My computer says this position is
good for Black, but I wouldn't like to play it.}) (24... Qh5?? 25. Rf3 Nf5 26. g4
{I lose the knight.}) 25. Rf3 Ne4 26. Bxe4 (26. Qc2 f5! {Now either my knight gets a permanent outpost or White is forced to open
files for the rook.} 27. exf6 Nxf6 28. Bxf6 Qxc2 {I stopped calculating here.
White can't force a capture on h7, so I have nothing to worry about.}) 26...
Qxe4 {I made a piece trade (more &quot;standard&quot; knowledge) and now White's attack
looks weak.} 27. e6 f6 28. exd7 Rad8 {I stopped calculating here, since I will
win the pawn and there is no danger to my position.} *
</code></pre>
<p>This is not to say that my analysis is perfect--the computer objects to various things I've said here, the most glaring of which is that it's actually quite tricky to deal with 26. Bd4. The only purpose of the answer is to give an example of a human thought process in a very complicated position with material advantage, and to emphasize that the material advantage doesn't dominate the analysis--it is just blended in with the other positional features.</p>
 14340: <p><strong>First consider the difference between a 'truly' won position vs a 'theoretically winning' position</strong>. By that I mean - a position that is within your own abilities to convert to a win, in a way you can already see, vs a position that seems like it 'should be winning'. You see that stockfish says the position was -3.1, but at your rating level, -3.1 isn't 'truly' won -  first of course because you point out that you can't see how to convert it, and second simply because at your current level, it would be very natural to overlook a tactic that you or your opponent could perform with a larger impact than a 3 point material swing.</p>
<p>So move away from calling a position like this 'won'; it could lead you to let your guard down. At the same time, a 3 point advantage 'should' be enough to convert to a win <em>with perfect play</em>, in most cases.</p>
<p><strong>So what gets in the way of you converting this 'theoretically winning' position to a 'truly won' position? Complexity.</strong> Particularly at your level of play, but really in all levels of chess, complexity and asymmetry <em>is an advantage to the player on the backfoot</em>.</p>
<p>Imagine an endgame where you have a rook and nothing else, and I just have a king. This should be a 100% won game (and if you don't consider that completely won, work on your endgames, so that you can convert a win in any circumstance where your opponent has only a bare king, and you have a minimum of material). Now now add 2 pawns and a knight for each of us to the board. Where before you would be able to easily slide your rook away from my king and make the mechanical advance that leads to checkmate, now you need to be cautious - are my pawns able to make a break for the 8th rank? Can my knight fork your rook and king? Is your knight trapped by the position of your own pieces? **Complexity has created the opportunity for you to make a mistake, and the same &quot;5 point material advantage&quot; of an extra rook is not so straightforward to convert to a win.</p>
<p><em><strong>So reduce the complexity</strong></em>. Trade everything down until you have a rook and I have nothing. You indicate this is what you're trying to do, but that your trades are 'refused'. You will need to become better at 'forcing' trades. If you fork my knight and king with your knight, and your knight is protected, you have forced me to take your knight. Simply moving your knight in view of mine to 'tempt' me to take it requires me to choose to do so - as you rise in your chess level, your opponents will more often have their own plans, and you should never rely on someone 'being bad enough that they will play the way I want', always try to play in a way that doesn't require mistakes on the part of your opponent.</p>
<p><em><strong>And reduce the asymmetry</strong></em>. Imagine you have a rook and 2 pawns, and I have a rook. Because we both have the same major piece, I can't attack your rook in a way that your rook can't attack back. Tactics might be possible on my part (skewering your king with your rook behind, as an example), but mostly your position is similar (but better) than mine. Asymmetry creates complexity that allows tactics to develop. Imagine instead I have a bishop and 2 pawns, and you have a rook and 2 pawns. From a material standpoint, this is still you being 'two pawns-worth of material' ahead, but now my bishop can attack your rook in a way that you can't immediately attack back, and my bishop also defends my pawns differently - it can become part of the pawn chain if needed, etc. Asymmetry naturally creates complexity, which creates the opportunity for me to prepare tactics, and also makes it easier for you to overlook something on the board.</p>
<p><strong>So your goal when it looks like you have enough material advantage to convert to a win</strong> (as mentioned in other answers, the way to know this is to practice your endgames - for example are you confident in your ability to checkmate with a bishop and knight only?) would be as the mid-game winds down, to:</p>
<p>(1) Play defensively. Keep your pieces connected and close to eachother. Being aggressive can be risky, and you no longer need risk to win, you need simplicity. Don't overlook your opponent's threats, deal with them, even if it seems slower than a 'near checkmate' that you can't quite calculate but you think is probably there. Keep in mind that for a sub ~1600 rated player, the most immediate improvement to your play will likely be just to not 'drop' / 'hang' pieces. Simply by defending all your pieces, you will be doing something that your opponents are not always doing.</p>
<p>(2) Simplify. Force trades of material. Reduce asymmetry.</p>
<p>(3) Watch for potential pawn breaks, on your side and the opponents. 2 connected pawns on the 6th rank are worth about as much as a rook, so don't ignore the threat of promotion, even if you feel you have a material advantage.</p>
<p>(4) Keep your opponent's king &quot;out of the game&quot;, by pushing it into a corner, especially preventing it from approaching your opponent's connected pawns. A king next to 2 pawns on the 6th rank is quite frightening indeed.</p>
<p>(5) <em>When safe</em> bring your own king into the game. As the material on the board simplifies, the relative power of a king increases, especially if there are no queens on the board, and even more so if there are no rooks on the board. If you're '2 points of material' ahead, but your opponent uses their king and you don't use yours, you will be unlikely to convert to a win.</p>
<p>(6) Checkmate using simple principles once the dust has settled. Really learn your endgames so that you are confident in all simplistic checkmates (especially with a single rook, and a single pawn - sometimes a single pawn is winning, sometimes it is a draw, you absolutely must learn how to win with a single pawn, because that's how a 1 point material advantage converts to a win).</p>
 15223: <p>I remember reading about this from one of GM Yasser Seirawan's books. What you want to do is:</p>
<ul>
<li>Pick a target</li>
<li>Figure out how to attack it</li>
</ul>
<p>In this case the obvious target is the White pawn on a3. Why this pawn? Because it cannot move (a4 bxa4 wins the pawn). It stands to reason it's easier to attack something that cannot move. The a3-pawn is also not easy to defend - it can no longer be defended by a pawn, so it must be defended by pieces, and you have more powerful pieces.</p>
<p>Your last move 34...Nc4 accomplishes this goal of hitting the pawn. White can't defend it anymore. Next turn, you play 35...Nxa3 which increases your material advantage, and now you pick a new target - this time the pawn on b4. The reason is the same, it cannot move and it cannot be defended by a White pawn. Once you have identified the target it becomes easy to plan how to take it: you play ...Rc4, ...Nc6, ...Qb1, etc, and then you will have more attackers than White has defenders. After you grab the b4-pawn you have powerful connected passed pawns that you can shepherd to promotion &amp; victory.</p>
<p>Note this analysis is superficial - 35.a4 bxa4?? actually loses you most of your advantage according to Stockfish - but that is because of the specifics of the position (in this case, White's bishops are actually quite threatening to your King).</p>
<p>One more thing: because you are ahead in material, another powerful plan is to force trades. Your opponent will be trying their darnedest not to acquiesce, but a material advantage lets you create threats that your opponent cannot parry. In the final position for example, an immediate threat you have is ...Qd2. If opponent does not trade queens, you take the bishop on a2. If White plays 35.Qg3 for example, then ...Qc2 traps the bishop and forces another trade (of course, you will have to defend against the threatened Qxg7# first).</p>
 4418: <p>There are two key things you need to do.</p>
<p>The first is to know how to win a won endgame. You do that by studying endgames. That will do two important things for you. Apart from teaching you how to win a won endgame, it will also teach you to recognise which endgame positions are won, and which are drawn, despite your material advantage. That way when you are in a winning middlegame you know what kind of endgame you are aiming for.</p>
<p>The second really important thing to do is to keep on fighting. The aim is not to get a winning middlegame position, it is to win the game. To that end a winning middlegame position is just one stop on the way to your real desired destination.</p>
<p>If you are driving to visit friends or family and you stop two thirds of the way there for petrol (or gas if you live in the US) you don't stop because you think you have arrived. You carry on after the stop, in just the same way as you did before the stop, except that you are no longer worried that you are going to run out of fuel (or not win the game).</p>
<p>This tendency to sit back once you have a theoretically winning position is something which affects all players. You have to fight it by trying even harder to not let your opponent back into the game and to win it yourself. Perhaps one good way of doing this is by starting each think about your next move by asking yourself &quot;Why did my opponent do that? What are they trying to do? How can I stop them?&quot;</p>
