user1315: I know that some moves from some opening can transpose to another.
But if I move my knight first, does it have benefit to me? In my Houdini, it shows lower value than I move a pawn first.
Best Regards,
Ahmad

user13012: 
NC3 should not be underestimated. There is an excelent book called "Knight on the Left" by Harald Kielhack, that is also among the best general chess book I know.
I normally open 1.e4 but about one game in eight I roll out 1.Nc3. Why? THere is no risk because there is no refutation. Quite often I get into standard open or semi-open positions with my opponent having used some extra time. And Black can get quickly into trouble with some very plausible moves


1.Nc3 e5 2.Nf3 Nc6 3. d4 exd 4. Nxd4 Nf6 5. Bg5 Be7 6. Nf5! 0-0 7. Nxe7+ Qxe7
8. Nd5 Qd8 9. Nxf6+ gxf6 10. Bh6 Re8 11.e3 with a very pleasant advantage.
I dont have general philosophical justification for you, 1.Nc3 offers not quite such a good chance of opening advantage as the four main moves, but it can be effective if you pick your opponents. PLayers who are prone to time trouble, players who will try too hard to refute it, players who know much more regular book than you do.

user-1: In general, where there are significant enough amount of games played in a particular position, there is little value in looking at a computer evaluation unless you're considering some deeper novelties. And that's especially true when looking at openings, which engines have been known to show errant evaluations for and for which engines generally use user-defined opening trees (strongly encourage using these for opening practice) anyway when playing in tournaments. 
A better way would be to look at actual game results. So, e.g. looking at the chessgames opening explorer win - draw - loss percentages 


e4  = 37.6% - 32.9% - 29.5%


d4  = 37.5% - 36.8% - 25.8%


Nf3 = 36% - 39.9% - 24.1%


c4 = 37.5% - 37.8% - 24.7%


Now, the numbers themselves might be confusing. More importantly are expected results


e4 = .376(1)+.329(.5) = .5405 points out of 1


d4 = .375(1)+.368(.5) = .559 points out of 1


Nf3 = .36(1)+.399(.5) = .5595 points out of 1


c4 = .375(1)+.378(.5) = .564 points out of 1


So is 1. Nf3 better than 1. d4 or e4? Probably not. And it's unlikely 1. c4 is some wondrous first move that produces better results than any other. More to the point, I would be willing to wager that any difference in results here is insignificant enough to warrant a change in opening move if you're more comfortable with another one. 
Also note, that the above doesn't take into account who plays the games, and many other factors. For example, one opening move may have a higher percentage of beginning player than another. 
And an interesting 2-part article on chessbase recently went in-depth into the e4/d4 debate and is probably an interesting read if you actually think one opening move is going to have a strong edge here. 

user2300: Using knight in first move is a good option, for instance 1Nf3 you can ilude your opponent to think you are gonna play reti or queens pawn or kings indian attack and also you avoid some crazy gambits . It's a good way of start for a queens pawn player because it reduces lots of theory

user2042: INTERLUDE:
I have answered many of your questions, and from that I conclude that you build some sort of a program or statistics.
The goal of the opening is to introduce as many pieces as possible, and to do it as fast as possible. In this process, your pieces must occupy the most aggressive squares available.
From the statistical point of view 1.e4 attacks 2 central squares and opens the best diagonals for the queen and bishop. 
d4can not develop queen aggressively, but opens the black bishop. 
These moves do not develop a piece, they only claim space ( in order to put a piece on those squares your opponent must exchange the pawn )  preparing the piece development.
Now let us look at the knight move:
1.Nc3->you develop a piece, you attack ( but do not claim! ) 1 central square and 1 on the wing, you fortify your own squares ( e4 and a4 ), but you do not open paths for other pieces.
1.Nf3->same as above, only different squares are attacked.
Why does knight move attack a square while pawn claims it? Because pawns have the lowest value, in order to put pieces at squares controlled by them you need to first exchange that pawn. Knight does not claim the square because you can challenge the knight more easily by putting the bishop/pawn/knight on that square. 
What is better-to develop pieces or to seize space first?
First 2 moves usually seize space, and are followed by piece development. Therefore, most games start with a pawn move, and then pieces are developed.
Statistically speaking, it is better to open with a pawn ( it claims important central squares and opens lines for the pieces to come out ) but chess is more than just statistics. 
So to answer your question:

What is the benefit of making the first move with a Knight? 

So what is the point of the knight move? To understand that observe these two examples-we shall consider only White's moves to preserve space:
1.e4 ... 2.Nf3 ... 3.Bc4 and 1.Nf3 ... 2.e4 ... 3.Bc4
In both cases we reach the same position. 
The point of the knight move is to get favorable transposition from one opening into another. It is used frequently to sidestep sharp variations, confuse opponent or "kick him out" of his opening. 
Objectively speaking, there is no difference between 1.e4/d4/Nf3/Nc3 because you will need to play them all at one point, it is all about move order. However, as someone pointed out, knight moves give opponents greater freedom of choice because they do not claim space. 
This means that "knight-first" player must learn more than "pawn-first" one but in return has a good chance to steer the game into variations he knows will be good for him which can not be said with 100% certainty for his opponent. Also, forcing opponent to play certain opening/line makes strong psychological impact on him.
This might seem insignificant to you, but in professional chess this "trick" is used often by stronger opponent.
To preserve space, I recommend you the book Andrew Soltis-Transpo tricks in chess*.
It will clarify what I have said in this post.
If you have further questions leave a comment.
Best regards.

user924: 1.Nf3 develops a piece, prevents 1...e5, gives black no targets (e.g. 1.e4 can be challenged with 1...d5 immediately) and keeps all options as far as pawn moves are concerned open.
Instead of choosing to place a pawn on e4, d4 or c4, white first sees what black's first move is. He may choose to play something like 2.g3 and 3.Bg2 to delay even further, depending.
That's quite a few benefits.

user35: Generally moving a knight first gives your opponent more ways to respond, so you have a lower chance to steer the game in the direction you want. On the other hand it gives you a little bit more flexibility, as you postpone the decision which pawn to move.

user2173: It's not worth it to analyze 1st moves with an engine. It's better to see possible variations in ChessBase's ECO view because you need to play opening which suits your mind style or antisuits your opponent's. An engine can't help you with that.

1315: <p>I know that some moves from some opening can transpose to another.</p>

<p>But if I move my knight first, does it have benefit to me? In my Houdini, it shows lower value than I move a pawn first.</p>

<p>Best Regards,<br>
Ahmad</p>
 13012: <ol>
<li><p>NC3 should not be underestimated. There is an excelent book called &quot;Knight on the Left&quot; by Harald Kielhack, that is also among the best general chess book I know.</p>
<p>I normally open 1.e4 but about one game in eight I roll out 1.Nc3. Why? THere is no risk because there is no refutation. Quite often I get into standard open or semi-open positions with my opponent having used some extra time. And Black can get quickly into trouble with some very plausible moves</p>
</li>
</ol>
<p>1.Nc3 e5 2.Nf3 Nc6 3. d4 exd 4. Nxd4 Nf6 5. Bg5 Be7 6. Nf5! 0-0 7. Nxe7+ Qxe7
8. Nd5 Qd8 9. Nxf6+ gxf6 10. Bh6 Re8 11.e3 with a very pleasant advantage.</p>
<p>I dont have general philosophical justification for you, 1.Nc3 offers not quite such a good chance of opening advantage as the four main moves, but it can be effective if you pick your opponents. PLayers who are prone to time trouble, players who will try too hard to refute it, players who know much more regular book than you do.</p>
 -1: <p>In general, where there are significant enough amount of games played in a particular position, there is little value in looking at a computer evaluation unless you're considering some deeper novelties. And that's especially true when looking at openings, which engines have been known to show errant evaluations for and for which engines generally use user-defined opening trees (strongly encourage using these for opening practice) anyway when playing in tournaments. </p>

<p>A better way would be to look at actual game results. So, e.g. looking at the <a href="http://www.chessgames.com/perl/explorer" rel="nofollow">chessgames opening explorer win - draw - loss percentages</a> </p>

<ul>
<li><ol>
<li>e4  = 37.6% - 32.9% - 29.5%</li>
</ol></li>
<li><ol>
<li>d4  = 37.5% - 36.8% - 25.8%</li>
</ol></li>
<li><ol>
<li>Nf3 = 36% - 39.9% - 24.1%</li>
</ol></li>
<li><ol>
<li>c4 = 37.5% - 37.8% - 24.7%</li>
</ol></li>
</ul>

<p>Now, the numbers themselves might be confusing. More importantly are expected results</p>

<ul>
<li><ol>
<li>e4 = .376(1)+.329(.5) = .5405 points out of 1</li>
</ol></li>
<li><ol>
<li>d4 = .375(1)+.368(.5) = .559 points out of 1</li>
</ol></li>
<li><ol>
<li>Nf3 = .36(1)+.399(.5) = .5595 points out of 1</li>
</ol></li>
<li><ol>
<li>c4 = .375(1)+.378(.5) = .564 points out of 1</li>
</ol></li>
</ul>

<p>So is 1. Nf3 better than 1. d4 or e4? Probably not. And it's unlikely 1. c4 is some wondrous first move that produces better results than any other. More to the point, I would be willing to wager that any difference in results here is insignificant enough to warrant a change in opening move if you're more comfortable with another one. </p>

<p>Also note, that the above doesn't take into account who plays the games, and many other factors. For example, one opening move may have a higher percentage of beginning player than another. </p>

<p>And an interesting <a href="http://en.chessbase.com/author/matthew-wilson" rel="nofollow">2-part article on chessbase</a> recently went in-depth into the e4/d4 debate and is probably an interesting read if you actually think one opening move is going to have a strong edge here. </p>
 2300: <p>Using knight in first move is a good option, for instance 1Nf3 you can ilude your opponent to think you are gonna play reti or queens pawn or kings indian attack and also you avoid some crazy gambits . It's a good way of start for a queens pawn player because it reduces lots of theory</p>
 2042: <h2>INTERLUDE:</h2>

<p>I have answered many of your questions, and from that I conclude that you build some sort of a program or statistics.</p>

<p>The goal of the opening is to introduce as <strong>many</strong> pieces as possible, and to do it <strong>as fast</strong> as possible. In this process, your pieces must occupy <strong>the most aggressive</strong> squares available.</p>

<p>From the statistical point of view <code>1.e4</code> attacks 2 central squares and opens <strong>the best diagonals</strong> for the queen and bishop. </p>

<p><code>d4</code>can not develop queen aggressively, but opens the black bishop. </p>

<p><strong>These moves do not develop a piece</strong>, they <strong>only claim space</strong> ( in order to put a piece on those squares your opponent must exchange the pawn )  <strong>preparing</strong> the piece development.</p>

<p>Now let us look at the knight move:</p>

<p><code>1.Nc3</code>-><strong>you develop a piece</strong>, you attack ( <strong>but do not claim!</strong> ) 1 central square and 1 on the wing, you fortify your own squares ( <code>e4</code> and <code>a4</code> ), but you do not open paths for other pieces.</p>

<p><code>1.Nf3</code>->same as above, only different squares are attacked.</p>

<p>Why does knight move attack a square while pawn claims it? Because pawns have the lowest value, in order to put pieces at squares controlled by them you need to first exchange that pawn. Knight does not claim the square because you can <strong>challenge</strong> the knight more easily by putting the bishop/pawn/knight on that square. </p>

<p>What is better-to develop pieces or to seize space first?</p>

<p>First 2 moves usually seize space, and are followed by piece development. Therefore, most games start with a pawn move, and then pieces are developed.</p>

<p>Statistically speaking, <strong>it is better to open with a pawn</strong> ( it claims important central squares and opens lines for the pieces to come out ) but chess is more than just statistics. </p>

<p>So to answer your question:</p>

<blockquote>
  <p>What is the benefit of making the first move with a Knight? </p>
</blockquote>

<p>So what is the point of the knight move? To understand that observe these two examples-we shall consider only White's moves to preserve space:</p>

<p><code>1.e4 ... 2.Nf3 ... 3.Bc4</code> and <code>1.Nf3 ... 2.e4 ... 3.Bc4</code></p>

<p>In both cases we reach the same position. </p>

<p><em>The point of the knight move is to <strong>get favorable transposition</strong> from one opening into another. It is used frequently to <strong>sidestep sharp variations</strong>, confuse opponent or "kick him out" of his opening.</em> </p>

<p>Objectively speaking, there is no difference between <code>1.e4/d4/Nf3/Nc3</code> because <strong>you will need to play them all at one point</strong>, it is all about move order. However, as someone pointed out, knight moves give opponents <strong>greater</strong> freedom of choice because they do not <strong>claim space</strong>. </p>

<p>This means that "knight-first" player <strong>must learn more</strong> than "pawn-first" one but in return has a good chance to steer the game into variations he <strong>knows will be good for him</strong> which can not be said <strong>with 100% certainty</strong> for his opponent. Also, forcing opponent to play certain opening/line makes <strong>strong psychological impact</strong> on him.</p>

<p>This might seem insignificant to you, but in professional chess this "trick" is used often by <strong>stronger</strong> opponent.</p>

<p>To preserve space, I recommend you the book <em>Andrew Soltis-Transpo tricks in chess</em>*.</p>

<p>It will clarify what I have said in this post.</p>

<p>If you have further questions leave a comment.</p>

<p>Best regards.</p>
 924: <p><strong>1.Nf3</strong> develops a piece, prevents 1...e5, gives black no targets (e.g. 1.e4 can be challenged with 1...d5 immediately) and keeps all options as far as pawn moves are concerned open.</p>

<p>Instead of choosing to place a pawn on e4, d4 or c4, white first sees what black's first move is. He may choose to play something like 2.g3 and 3.Bg2 to delay even further, depending.</p>

<p>That's quite a few benefits.</p>
 35: <p>Generally moving a knight first gives your opponent more ways to respond, so you have a lower chance to steer the game in the direction you want. On the other hand it gives you a little bit more flexibility, as you postpone the decision which pawn to move.</p>
 2173: <p>It's not worth it to analyze 1st moves with an engine. It's better to see possible variations in ChessBase's ECO view because you need to play opening which suits your mind style or antisuits your opponent's. An engine can't help you with that.</p>
