user1211: Here's a game of mine from last night.  It was my first tournament game for many years.
(This game is David Kenney vs. Douglas Stones [me] 1-0.  Press F to flip the board.)
[fen ""]
[Event "Bluenose Chess Club Tournament"]
[Site "Halifax"]
[Date "2013"]
[Round "1"]
[White "David Kenney"]
[Black "Douglas Stones"]
[Result "1-0"]

1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 c6 5.e3 Bd6 6.Bd3 O-O 7.O-O Nbd7 8.e4 dxe4
9.Nxe4 Nxe4 10.Bxe4 Qc7 11.Re1 Nf6 12.Bc2 Re8 13.Bg5 Nd7 14.Qd3 Nf8 15.
Rad1 b6 16.a3 Bb7 17.b4 Rac8 18.c5 Be7 19.Re4 bxc5 20.dxc5 Rcd8 21.Qe2 
Rxd1+ 22.Qxd1 Rd8 23.Rd4 Rd5 24.Bxe7 Qxe7 25.Be4 Rxd4 26.Qxd4 Nd7 27.Ne5 
Nxe5 28.Qxe5 Qd7 29.Qd6 Qc8 30.b5 g6 31.Bxc6 Kg7 32.Qd7 Qf8 33.Qd4+ e5 34.
Qxe5+ f6 35.Qc7+ Kh6 36.Bxb7 Qe8 37.Qf4+ Kg7 38.Qb4 Qd7 39.Bf3 Qe7 40.g3 1-0

I didn't (seem to) make any tactical blunders, yet seem to have slowly been ground down to a loss via positional play.

Question: How can I avoid this happening in the future?

It's unclear to me how I could do that; some things spring to mind:

Aim for more tactical openings.
Gain familiarity with the usual endgame pawn structures and piece combinations in the chosen opening.
Study grandmaster games which were decided by positional play.

(Meta-comment:  This question is motivated by the specific game above, but answers should ideally be of general interest, i.e., in the some of the themes will hopefully be useful and interesting category mentioned in this meta thread.)

user1610: It is the typical problem of falling into a cramped position. Think twice before giving up the center (8...dxe4), and plan what kind of breaks you have in order to open the position.
In my opinion, the game is practically lost with 16...Bb7. The only chance for black is to go for the c5 break. And the move maybe was 16...Ba6 (and then c5).
Also notice that you cannot put your knight on d5 (for tactical reasons), so the game after c5 is practically over (the white pieces have more space and they can move towards the black king very easily) and the black bishop is a piece of wood ...).
And it is true that when you are playing in a position like that it is convenient to exchange pieces... but in this case, it is not recommended because you have a very bad bishop. So at the end (like in the game), you are practically playing without a whole piece.

user1161: It seems to me that the theme of this game is strategic play. I am speaking of tactical play as things that you can force, specific moves that have a definite best play and lead to a specific result. Strategic play being moves made of less concrete reasons because there are not tactical considerations to play at the moment. This includes things like space, king safety, active bishops, open or closed positions, controlling open lines, etc. 
In general tactical possibilities arrise from good strategic play, in this game the major factors seemed to be control of the center and space. White has control of over half the board most of the time, and maintains control of the center. 

user606: after 18... Be7, you do have a nice target on d4 to point your rooks at.  Instead of resolving the tension, you might have tried that, maybe with a plan of Qc8-Ba6 to free the light squared bishop.  There is a lot of pressure on your kingside, and your pieces don't seem well placed to defend.

user1193: I like to see everything through lenses of tactics that can be exploited. You allowed your pawn to be permanently pinned to the bishop. This can be argued as a strategic mistake, but it ends with a quite tactical resolution, where the threat of b5 is exploited. I would say, to avoid similar results, you need to make sure (maybe by using tactics!) that you do not end up with bad pieces, forever pinned and blocked. Here your 17... Rac8 allowed the c5- which may be, not a tactical blunder, but lack of tactics! Did you have a look at 17... c5!?. I am not sure if this does not lose a pawn, but sometimes it may be worth giving a pawn, for a superior position. Try to play this against a friend (or a reasonably set up computer) after this move. See how you like it. If this is the problem, then it was not a tactical mistake- it was a lack of a tactical reply, lack of momentum in your play. You allowed your superior position to melt away...

user1506: You can also lose a game due to positional mistakes.
For instance

you have some weak squares, where the opponent can place some
pieces, which will just dominate against your pieces (for example a knight on your 3rd/4th rank)
some weak pawns, which are easy to attack but hard to defend (the more they are ahead, the easier it is to attack them)

Your white-squared bishop needed 16 moves to develop.
I can't see why you placed your knight on f8. It is just useless there. You are just giving space away, which the opponent can and will use (c4, b4, c5 and so on).
Your pawn structure on the queen side is disastrous. Especially after bxc5. I would have tried to push c5 with black.
Basically you played without a real plan. You tried to defend (maybe hoping for a draw) but it didn't work.

How can you avoid it?

Take your time in the game and try to figure out a plan. Also try to figure out what your opponent wants to do. It's really hard to find a good plan in certain games, but you will get better and better. If you don't do anything during the game, you will get destroyed (as you can see in your last game).

user1241: Grandmasters (and below) often lose because a tiny strategic advantage has been slowly worked up into an indefensible position.
Like boxing. You can lose in an instant if a quick attack KOs you. Or you can be ground down over twelve rounds by someone who has:

slightly better stamina to start with
avoids losing to your tactical flurries

Many players crack under pressure and we see a tactical end to a strategic game. But that crack was partially caused by playing on the backfoot for so long as the strategic advantage slowly blossomed.

user17: I didn't like your 14... Nf8. Would have played g6 (as you later did).
IMHO, White won the game by playing, 18. c5 which your N on d7 was posted to prevent.
This is a strategic, not tactical issue.
For a more tactical opening, I would have refrained from 3....d5, playing b6 instead, and aimed for Queen's Indian with 4. ... B b7 or a Nimzo-Indian with 4....Bb4 after White's 4. Nc3. See the 1948 Botvinnik-Reshevsky Nimzo-Indian game, which Black won. (I found it highly instructive.)

user167: This answer is something of a kindred spirit to those already given by dfan and jedrus07; both of their answers focus on your light-square bishop, with dfan addressing the big strategic picture that often revolves around that piece and jedrus07 focusing on the concrete pickle it ended up in by the end. I want to share a few thoughts on how its fate and yours might have been improved.

The matter of c5. 18.c5 definitely cramps Black's position, especially because it fixes that c6 pawn, and incidentally lets the white queen eye a6, keeping your light-square bishop off the a6-f1 diagonal. For that reason, you probably should have put the bishop on a6 to begin with with 16...Ba6, as a way to get some activity for that piece and restrict White's options on the queenside. Really it's a better home for the bishop than b7 would be even if the c6 pawn didn't get stuck in place.
After 18.c5 you (correctly, I think) retreated instead of capturing, but then you ended up doing so the next move anyway. With 18...Be7 19.Re4 bxc5 you allow White to rid himself of the backward d-pawn which could have become a target and as much of a liability as your own c-pawn; IMO your 19th move was a mistake that makes White's position easier to play. [Note: Stockfish disagrees with at least part of my reasoning here, as it actually suggests 20.bxc5 instead of 20.dxc5. As a practical matter of making White's life easier, at least at the amateur level, for the moment I stand by my comment anyway.]

Trading a piece you shouldn't. By the time of 26.Qd4 Black already has quite a difficult defense, as protecting c6 will be a permanent chore. Keeping the white knight out of e5 by 26...f6 would be a good beginning to the defense. But 26...Nd7? makes White's task much easier, and the mistake here falls under the general area of trading the wrong pieces. I'm not suggesting you necessarily meant to initiate the trade of knights, but only that the reason this non-blunder move is a serious mistake is that it presents White the opportunity to effect that exchange. The problem is that the trade of knights amplifies how much better White's remaining pieces are than yours, and puts your concrete task of saving c6 out of reach.
I mention this especially because whether (and what pieces) to exchange is a very common dilemma over the course of a game -- Should I aim for an endgame here or not? Do I need to keep a pair of rooks on the board, or trade everything off? etc. -- and such decisions are permanent and often more consequential than many players realize. Again, I doubt you intended to make this trade happen, but on the flip side, White was absolutely correct to force your hand with 27.Ne5!, and I think it was his consistently taking advantage of such not-purely-tactical opportunities that ultimately led to your defeat.



user291: In this case, the answer is "gain familiarity with the standard strategical themes of the chosen opening".
Black's #1 issue in the Queen's Gambit Declined is what to do with his light-squared bishop, which if ignored can easily get stuck behind the e6 pawn and often a c6 pawn. The two standard ways to free it are

Play ...e5 to allow the bishop to move along the c8-h3 diagonal
Play ...b6 and ...c5 and place the bishop on b7

You kind of got halfway through plan #2, but once White got c5 in, your bishop had no future.
Concentrate on freeing your light-squared bishop the next time you play the Queen's Gambit Declined and you'll be much less likely to get ground down like this. This takes priority over moves like 11...Nf6 (which you just moved back two moves later anyway) and 12...Re8.

1211: <p>Here's a game of mine from last night.  It was my first tournament game for many years.</p>

<p>(This game is David Kenney vs. Douglas Stones [me] 1-0.  Press <kbd>F</kbd> to flip the board.)</p>

<pre><code>[fen ""]
[Event "Bluenose Chess Club Tournament"]
[Site "Halifax"]
[Date "2013"]
[Round "1"]
[White "David Kenney"]
[Black "Douglas Stones"]
[Result "1-0"]

1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 c6 5.e3 Bd6 6.Bd3 O-O 7.O-O Nbd7 8.e4 dxe4
9.Nxe4 Nxe4 10.Bxe4 Qc7 11.Re1 Nf6 12.Bc2 Re8 13.Bg5 Nd7 14.Qd3 Nf8 15.
Rad1 b6 16.a3 Bb7 17.b4 Rac8 18.c5 Be7 19.Re4 bxc5 20.dxc5 Rcd8 21.Qe2 
Rxd1+ 22.Qxd1 Rd8 23.Rd4 Rd5 24.Bxe7 Qxe7 25.Be4 Rxd4 26.Qxd4 Nd7 27.Ne5 
Nxe5 28.Qxe5 Qd7 29.Qd6 Qc8 30.b5 g6 31.Bxc6 Kg7 32.Qd7 Qf8 33.Qd4+ e5 34.
Qxe5+ f6 35.Qc7+ Kh6 36.Bxb7 Qe8 37.Qf4+ Kg7 38.Qb4 Qd7 39.Bf3 Qe7 40.g3 1-0
</code></pre>

<p>I didn't (seem to) make any tactical blunders, yet seem to have slowly been ground down to a loss via positional play.</p>

<blockquote>
  <p><strong>Question</strong>: How can I avoid this happening in the future?</p>
</blockquote>

<p>It's unclear to me how I could do that; some things spring to mind:</p>

<ul>
<li><p>Aim for more tactical openings.</p></li>
<li><p>Gain familiarity with the usual endgame pawn structures and piece combinations in the chosen opening.</p></li>
<li><p>Study grandmaster games which were decided by positional play.</p></li>
</ul>

<p>(<em>Meta-comment</em>:  This question is motivated by the specific game above, but answers should ideally be of general interest, i.e., in the <em>some of the themes will hopefully be useful and interesting</em> category mentioned in <a href="https://chess.meta.stackexchange.com/q/130/">this meta thread</a>.)</p>
 1610: <p>It is the typical problem of falling into a cramped position. Think twice before giving up the center (8...dxe4), and plan what kind of breaks you have in order to open the position.</p>

<p>In my opinion, the game is practically lost with 16...Bb7. The only chance for black is to go for the c5 break. And the move maybe was 16...Ba6 (and then c5).</p>

<p>Also notice that you cannot put your knight on d5 (for tactical reasons), so the game after c5 is practically over (the white pieces have more space and they can move towards the black king very easily) and the black bishop is a piece of wood ...).</p>

<p>And it is true that when you are playing in a position like that it is convenient to exchange pieces... but in this case, it is not recommended because you have a very bad bishop. So at the end (like in the game), you are practically playing without a whole piece.</p>
 1161: <p>It seems to me that the theme of this game is strategic play. I am speaking of tactical play as things that you can force, specific moves that have a definite best play and lead to a specific result. Strategic play being moves made of less concrete reasons because there are not tactical considerations to play at the moment. This includes things like space, king safety, active bishops, open or closed positions, controlling open lines, etc. </p>

<p>In general tactical possibilities arrise from good strategic play, in this game the major factors seemed to be control of the center and space. White has control of over half the board most of the time, and maintains control of the center. </p>
 606: <p>after 18... Be7, you do have a nice target on d4 to point your rooks at.  Instead of resolving the tension, you might have tried that, maybe with a plan of Qc8-Ba6 to free the light squared bishop.  There is a lot of pressure on your kingside, and your pieces don't seem well placed to defend.</p>
 1193: <p>I like to see everything through lenses of tactics that can be exploited. You allowed your pawn to be permanently pinned to the bishop. This can be argued as a strategic mistake, but it ends with a quite tactical resolution, where the threat of b5 is exploited. I would say, to avoid similar results, you need to make sure (maybe by using tactics!) that you do not end up with bad pieces, forever pinned and blocked. Here your 17... Rac8 allowed the c5- which may be, not a tactical blunder, but lack of tactics! Did you have a look at 17... c5!?. I am not sure if this does not lose a pawn, but sometimes it may be worth giving a pawn, for a superior position. Try to play this against a friend (or a reasonably set up computer) after this move. See how you like it. If this is the problem, then it was not a tactical mistake- it was a lack of a tactical reply, lack of momentum in your play. You allowed your superior position to melt away...</p>
 1506: <p>You can also lose a game due to positional mistakes.</p>

<p><strong>For instance</strong></p>

<ol>
<li>you have some weak squares, where the opponent can place some
pieces, which will just dominate against your pieces (for example a knight on your 3rd/4th rank)</li>
<li>some weak pawns, which are easy to attack but hard to defend (the more they are ahead, the easier it is to attack them)</li>
</ol>

<p>Your white-squared bishop needed 16 moves to develop.</p>

<p>I can't see why you placed your knight on <code>f8</code>. It is just useless there. You are just giving space away, which the opponent can and will use (<code>c4</code>, <code>b4</code>, <code>c5</code> and so on).</p>

<p>Your pawn structure on the queen side is disastrous. Especially after <code>bxc5</code>. I would have tried to push <code>c5</code> with black.</p>

<p>Basically you played without a <strong>real</strong> plan. You tried to defend (maybe hoping for a draw) but it didn't work.</p>

<blockquote>
  <p>How can you avoid it?</p>
</blockquote>

<p>Take your time in the game and try to figure out a plan. Also try to figure out what your opponent wants to do. It's really hard to find a good plan in certain games, but you will get better and better. If you don't do anything during the game, you will get destroyed (as you can see in your last game).</p>
 1241: <p>Grandmasters (and below) often lose because a tiny strategic advantage has been slowly worked up into an indefensible position.</p>

<p>Like boxing. You can lose in an instant if a quick attack KOs you. Or you can be ground down over twelve rounds by someone who has:</p>

<ol>
<li>slightly better stamina to start with</li>
<li>avoids losing to your tactical flurries</li>
</ol>

<p>Many players crack under pressure and we see a tactical end to a strategic game. But that crack was partially caused by playing on the backfoot for so long as the strategic advantage slowly blossomed.</p>
 17: <p>I didn't like your 14... Nf8. Would have played g6 (as you later did).</p>

<p>IMHO, White won the game by playing, 18. c5 which your N on d7 was posted to prevent.</p>

<p>This is a strategic, not tactical issue.</p>

<p>For a more tactical opening, I would have refrained from 3....d5, playing b6 instead, and aimed for Queen's Indian with 4. ... B b7 or a Nimzo-Indian with 4....Bb4 after White's 4. Nc3. See the 1948 Botvinnik-Reshevsky Nimzo-Indian <a href="http://www.chessgames.com/perl/chessgame?gid=1032174" rel="nofollow">game,</a> which Black won. (I found it highly instructive.)</p>
 167: <p>This answer is something of a kindred spirit to those already given by <a href="https://chess.stackexchange.com/a/2282/167">dfan</a> and <a href="https://chess.stackexchange.com/a/2330/167">jedrus07</a>; both of their answers focus on your light-square bishop, with dfan addressing the big strategic picture that often revolves around that piece and jedrus07 focusing on the concrete pickle it ended up in by the end. I want to share a few thoughts on how its fate and yours might have been improved.</p>
<ol>
<li><p><em>The matter of c5.</em> <code>18.c5</code> definitely cramps Black's position, especially because it fixes that c6 pawn, and incidentally lets the white queen eye a6, keeping your light-square bishop off the a6-f1 diagonal. For that reason, you probably should have put the bishop on a6 to begin with with <code>16...Ba6</code>, as a way to get some activity for that piece and restrict White's options on the queenside. Really it's a better home for the bishop than b7 would be even if the c6 pawn didn't get stuck in place.</p>
<p>After <code>18.c5</code> you (correctly, I think) retreated instead of capturing, but then you ended up doing so the next move anyway. With <code>18...Be7 19.Re4 bxc5</code> you allow White to rid himself of the backward d-pawn which could have become a target and as much of a liability as your own c-pawn; IMO your 19th move was a mistake that makes White's position easier to play. [Note: Stockfish disagrees with at least part of my reasoning here, as it actually suggests <code>20.bxc5</code> instead of <code>20.dxc5</code>. As a practical matter of making White's life easier, at least at the amateur level, for the moment I stand by my comment anyway.]</p>
</li>
<li><p><em>Trading a piece you shouldn't.</em> By the time of <code>26.Qd4</code> Black already has quite a difficult defense, as protecting c6 will be a permanent chore. Keeping the white knight out of e5 by <code>26...f6</code> would be a good beginning to the defense. But <code>26...Nd7?</code> makes White's task much easier, and the mistake here falls under the general area of <em>trading the wrong pieces</em>. I'm not suggesting you necessarily meant to initiate the trade of knights, but only that the reason this non-blunder move is a serious mistake is that it presents White the opportunity to effect that exchange. The problem is that the trade of knights amplifies how much better White's remaining pieces are than yours, and puts your concrete task of saving c6 out of reach.</p>
<p>I mention this especially because whether (and what pieces) to exchange is a very common dilemma over the course of a game -- Should I aim for an endgame here or not? Do I need to keep a pair of rooks on the board, or trade everything off? etc. -- and such decisions are permanent and often more consequential than many players realize. Again, I doubt you intended to make this trade happen, but on the flip side, White was absolutely correct to force your hand with <code>27.Ne5!</code>, and I think it was his consistently taking advantage of such not-purely-tactical opportunities that ultimately led to your defeat.</p>
</li>
</ol>
 291: <p>In this case, the answer is "gain familiarity with the standard strategical themes of the chosen opening".</p>

<p>Black's #1 issue in the Queen's Gambit Declined is what to do with his light-squared bishop, which if ignored can easily get stuck behind the e6 pawn and often a c6 pawn. The two standard ways to free it are</p>

<ul>
<li>Play ...e5 to allow the bishop to move along the c8-h3 diagonal</li>
<li>Play ...b6 and ...c5 and place the bishop on b7</li>
</ul>

<p>You kind of got halfway through plan #2, but once White got c5 in, your bishop had no future.</p>

<p>Concentrate on freeing your light-squared bishop the next time you play the Queen's Gambit Declined and you'll be much less likely to get ground down like this. This takes priority over moves like 11...Nf6 (which you just moved back two moves later anyway) and 12...Re8.</p>
