I’m ready to capture opponents queen on c8. It will also be a check, however as soon as I promote my pawn it will be captured by one of my opponents rooks. When considering whether to promote to a queen or something else, if I lose the promoted queen, during a material count or points perspective would it better to lose a knight instead of a queen?
2 Answers
It does not matter what piece is lost from a material count perspective. It is true that for one half-move, you will have more or less material on the board. However, it is not useful to count your material before the end of a forcing sequence. The material count at the end of the sequence is what matters, not halfway through.
The "material count" in chess is a purely analytical concept, it is not formalized in the rules at all. It's a good heuristic to help guide your play, but you should always be concerned about the concrete nature of the position before material.
In short: There is no "score" in chess, so it doesn't matter what piece your opponent captured after you promoted.
The only time to consider underpromoting is when there are weird stalemating or checkmating patterns (the "concrete nature of the position"). Or to disrespect your opponent who should have resigned already.
A mathematicians answer. Psychologically, your thoughts are valid: maybe if you promote to something cheap, maybe your opponent won't recapture and looks for more valuable victims. But since chess is a two player zero sum game with complete information, giving your opponent additional options never can be beneficial to your position. What is captured on c8 stays on c8, the total is in any case -1 pawn for you, -1 queen for the opponent, regardless of the promoted piece recaptured on c8.
This analysis of course critically hinges on the assumption that recapturing on c8 is the best move of the opponent. But it might be that your new queen on c8 is the cause for a devious stalemate of Black by another, non-recapturing move. In that case, underpromote indeed!
- Thanks for taking the time to respond. I now remember reading something about creating a stalemate situation. I’ll go back and read up on this again.Bill E– Bill E2025-04-16 12:37:28 +00:00Commented Apr 16 at 12:37
- Consider: Kc6, Pb7, Pd7 - Ka7, Nc8, Rh8. In the first move, you should promote to queen, even a rook leads to Rh6+ and draw. Black surely plays Rxc8+ (even if Rh6+ prolongs the game). Now you should promote to rook, since queen stalemates.Hauke Reddmann– Hauke Reddmann2025-04-16 19:15:18 +00:00Commented Apr 16 at 19:15