dmp4373 wrote on 05/15/10 at 19:25:06:
I understand your reasoning and it's logical, but it fails to recognize the very real situation that often occurs where an advantage exists, yet there is no way to forcefully exploit it. Here is an example of my point; White has a lead in development and all other things are equal. There is no way for white to cash in on that lead and so black gradually catches up in development and the position goes from += to =.
By your reasoning, white's advantage was an illusion and didn't actually exist.
Exactly.
dmp4373 wrote on 05/15/10 at 19:25:06:
But evaluations are based on the static and dynamic elements of a position at a given moment. White really did have a lead in development and therefore really did have the advantage at that point in time.
This is not really a contradiction. An advantage can be meaningless. This especially happens to temporary advantages like a lead of development or a badly placed peace.
I have had an extreme example of the latter in one of my games. In a Volga Gambit I had a knight on b6, my opponent doubled pawns on b2 and b5. I played Nb6-a8. According to your logic White at that moment had a real advantage (extra pawn and that knight on one of the worst squares of the board. Just a move later I played Na8-c7 (I had foreseen that White could not prevent it; big deal) after which I soon won back pawn b5 with an advantage. I won the game.
So according to you within two moves the correct evaluation went from more or less equal (blockading Knight on b6 offered enough compensation) to good for White to good for Black within two moves.
Does not make any sense. The point is of course that dynamic play requires separating real advantages and weakness from virtual ones. As Kortchnoi and Bronstein declared: a weakness is only a weakness if the opponent can take benefit from it. And exactly that is the question of all gambits: can the defender take benefit of the extra material? Concerning the BDG the debate continues.
dmp4373 wrote on 05/15/10 at 19:25:06:
You see this all the time in opening books with comments like, 'White has a slight advantage, but black should be okay.
Not in the opening books I have. Though I quite read often something like "White has a slight advantage, but Black has decent play." That's quite different.
Still I think I know what you mean. I have seen games in which one players maintains an edge until the very last move, when it proved not enough for a win. But as long as the BDG is not analysed until deep into the endgame this is not that relevant for the evaluation of this opening. If openings are indeed analysed until the very end only three evaluations remain: won, drawn, lost.
Btw I am curious how you evaluate a perfectly closed position in which one player has Queen and King and the other only a King; no way to invade. Evaluating that one as advantageous makes as much sense as evaluating a gambit that offers optical compensation iso real one as more or less equal. I have enough experience with the former. To distinguish the two is essential for any gambit player - and a very hard task.