Chess

[Gustaran]

After JKaen's mistake of Nd5 white has the advantage. What's amusing about this blunder is that it's intentions are good; trying to reduce material.

Indeed, but before going for exchanges one should make sure there is no immediate tactical threat. Also, I would recommend finishing the development first. It's just when presented with the choice between exchanging or moving away you exchange, because it doesn't make any difference in tempi. 12...Be6 13. Nb5 0-0-0 and White has nothing.

I also disagree that a pawn is as big of an advantage as you make it out to be. Remember the average rating of USCF is 657. There's a bunch of USCF members who only play a few games and get creamed. If you throw them out then I would guess the average rating is 1000 USCF. At that level it's only a matter of time until someone drops a piece and pawns really don't matter that much. (Although they are certainly worth the move it takes to capture them.)

And I am sure there are players that would simply hang their Queen, but frankly I don't judge positions from such a perspective.

One example: IIRC, in my first game against Jkaen he played very well and had a totally equal position until he blundered a single pawn and subsequently lost the endgame exactly because of that single pawn.
The truth is you can check any manual on positional play and you will find out that there are games on master level which are won because one side has two bishops and the other side bishop and knight (all else being equal). Even at 1500, if you have an extra pawn and don't hang anything until the end of the game you will usually at least secure a draw if there isn't a large disparity in player strength. Of course there are players that can't hold on to their pieces but in such a case the position is never truly winning because they might overlook a mate in one.

[Jkaen]

Yup, saw the threat of the fork, then got sidetracked instead of developing and dealing with it properly. Was hoping he would make a mistake and not take my bishop going for the rook instead, but unfortunately wasnt stupid enough to fall for that

[Gustaran]

Why not 15...Rb8 instead of Bd6?

[Jkaen]

He then moves his knight revealing a bishop attack on the rook as well as a knight attack on whatever other piece

[Gustaran]

as well as a knight attack on whatever other piece

On what other piece exactly? The only attacking move he has would have been Ne6, and only now Bd6 and after an exchange on d6 white gets his pawn back, but nothing else. And if Nb5, you just move the rook back to a8 - draw by repetition.

But ok, I guess we should stop analyzing every move of an ongoing game, it just goes to show that sometimes there are more resources available to you than you think. With a pawn for the exchange i still think every result is possible.

[MJW (ya that one)]

I have disagree that player strength can effect evaluation of things. For example, Knights are extremely dangerous to new players. I've heard Burgress in the "Mammoth book of chess" say that a knight fork is one of the top two reasons for a loss of a game. This would make Knights equal to bishops at that level. New players have trouble dealing with attacks making king safety and initiative (by being in control you stop attacking) more important. The Queen is also much easier to handle than the two rooks so new players should be hesitant to part with the Queen.

Also one pawn even at the GM-level isn't enough sometimes. I've remembered when Karpov was two pawns down with no real compensation, at a time disadvantage and even won the game! (This was the second game in the 2002 New York match). I've also heard a 2700+ GM failing to win a Queen+King vs. Rook+King endgame.

Also you should not relie on your opponent making a mistake like that, JKaen. Laying traps and psychological tricks are okay. But having a simple trap, that transforms your position from almost winning into almost losing if your opponent doesn't fall for it, is not okay.

[Gustaran]

Also one pawn even at the GM-level isn't enough sometimes. I've remembered when Karpov was two pawns down with no real compensation, at a time disadvantage and even won the game! (This was the second game in the 2002 New York match). I've also heard a 2700+ GM failing to win a Queen+King vs. Rook+King endgame.

Sorry, but that's pointless. Kramnik even once overlooked a mate in one in a drawn position, so should we say:"Well, white is up a queen, but the position is not winning, because he might overlook a mate in one like Kramnik did"?
Kasparov-Kramnik was a rapidplay game and of course the position is considered winning at some point with the two extra pawns.

At some point in time somewhere a GM certainy failed to win a won position, but that doesn't change the evaluation. Evaluation is always with best play. Example: I can't mate with bishop & knight vs. king, but it is well known that this is a mate in under 50 moves, you can even look it up in the tablebase. The evaluation of the position is clearly winning. If I don't know how to do it, that's my problem.

And a knight vs bishops is neither better or worse, it depends on the type of position. A knight on a protected outpost on the 6th rank can be even stronger than a rook, while in wide open position you would consider the two bishops an advantage.
I recommend tactics training for anyone who misses knight forks all the time and not to blindly trade off all enemy knights because you might miss a fork.

[MJW (ya that one)]

I really feel what the best move is influence by player-factors. If this weren't the case everyone would play 1.e4 or 1.d4 because people would have figured out what the best move is. Also everyone would agree to a draw before even playing because chess is a draw. I think I can cite two examples were the objectively better move is worse than a subjectively better move.

1. http://www.chessgames.com/perl/chessgame?gid=1111541 Were Spassky plays for a mating attacking instead of winning a rook. Playing for a mating attack is objectively better because it wins faster. He blows his load and allows black to escape. This allows the c3 pawn to take revenge against being laughed at and win the game.

2. The Opera Game. The best move was Bxf7+ winning two pawns and the game; not Nc3. After Nc3 black doesn't have to play b5 but he can try Na6 forcing BxN as white cannot allow the black knight to c5. After black recaptures his position is horrible but not two down pawns horrible. Yet everyone, including me, says that it is better to play Nc3 for being more artistic and pretty.

I'm sure there's many more. For example in his books Kasparov labeled a move Ke2(?!) because it was technically not the best move but the reason for it was almost impossible to happen in over the board play.

[Gustaran]

I really feel what the best move is influence by player-factors.

That is correct. Even Lasker once said that the best move in a position against a certain player may not be the best against another player.

One example: Statistically, the best scoring defense for black against 1.e4 is 1...c5, the Sicilian defense (probably Najdorf variation). So objectively, I should always answer 1.e4 with 1...c5. The only problem is that the Najdorf has accumulated a huge amount of theory and very often leads to super sharp positions for tacticians. One wrong move and black is lost.
Therefore, I opt to play the French which offers less counterplay but is more solid and fits my personal style.

However, you must always keep in mind that a good player should always know what the objectively best move is and have very good reason for not playing it. Many beginners are lazy and say things like: "I never trade Queens because I want to win in a brilliant kingside mating attack" and disregard the fact that the position calls for a completely different plan. In that case claiming there is no objectively best move is just an excuse for bad chess.

[uberfish]

Yeah I'm an e4 e5 player because the opening variations just make a lot more sense to me. My match opponent just resigned in my black game after a failed King's Gambit. I always like playing this as black because the extra pawn black gets immediately controls important squares, so if I avoid being mated early I have a counterattack ready to go.