Nevermind! I DONT see it! haha...
If Qxa2, Ra1; Qb2, Bc3 and the queen hangs?
But didnt they at least get an extra pawn or even a rook instead of Qxd4 and taking the knight immediately?
Can someone explain this move order by the 2500 computer?
Sort:
Two knights for a queen is better than just a rook or just a pawn for a queen.
http://en.m.wikipedia.org/wiki/Chess_piece_relative_value
(you probably mean Nxc7+ (=check) instead of Nxc7# (=mate), you had me confused there :))
I think the idea is that if you play Nxc7 immediately, you will lose the knight on d4, Rb1 forces the queen to move somewhere where it can't capture that piece.
Then, rather than losing a full rook, the computer prefers to trade the queen for 2 knights
May 25, 2015
0
#6
To contrast with the orignal computer line suggested - after Qxa2 white retains the two developed central knights and the threats they offer (which is worth far more than the rook and pawn in this setting, with only one open file); since there is no good way to defend the threat of Nxc7+ without several exchanges occuring, Black stands worse.
Stockfish goes for Rb2.
Thanks all! After the two knights are better than a rook/pawn I figured it out. The problem I was having is that I was forgetting that after Qxd4, Nxd4, then Nxd4... so its two knights for the queen. I kept thinking that it was only one knight, so why not take the rook/pawn ect...
I do understand now why its a blunder, because I could win the queen instead of the rook with check.
I now realize the queen was trapped after Rb1, and that Qxa2 does not give it any room for escape, which in the game I thought it did.
Also, after realizing that two knights were falling for the queen, it makes sense why they would take the 6 points for two centeral knights vs 6 points from a benign pawn and rook.
Sub1000: Advanced lesson for you. Pieces are generally considered to be actually worth slightly more than 3 points (especially bishops, and especially both bishops). Two pieces for a rook and pawn is, everything being average (if there is such a thing) not a good trade. Of course, the values are close enough that it might be good in a particular case, advanced players play the board, not some abstract values, but if you dont have a particular reason for the trade, never voluntarily give up two pieces for a rook and pawn. You found specific valid reasons pointing the other way, but didnt seem to know the general principle so I thought I'd share it.
ArtNJ wrote:
Sub1000: Advanced lesson for you. Pieces are generally considered to be actually worth slightly more than 3 points (especially bishops, and especially both bishops). Two pieces for a rook and pawn is, everything being average (if there is such a thing) not a good trade. Of course, the values are close enough that it might be good in a particular case, advanced players play the board, not some abstract values, but if you dont have a particular reason for the trade, never voluntarily give up two pieces for a rook and pawn. You found specific valid reasons pointing the other way, but didnt seem to know the general principle so I thought I'd share it.
I did know that minor pieces are generally worth 3 points each and can actually change in different circumstances. I know that bishops with long diagonals are worth more than a white bishop against a closed black pawn chain (or whatever) and in this case those two knighs are clearly worth more since they attack the whole center, can give immediate checks, ect. vs. the benign rook and pawn. The main reason why I couldnt figure this out is because I completly overlooked that two knights fall in exchange for the queen. I kept thinking over and over that the computer wanted to capture the one knight vs a rook and pawn. Then I went into all these crazy thoughts about possible backrow or smother mates that I couldnt see, and perhaps the computer did not mention since they were not forced mates.
After the two knights comment it instantly made sense.
Thanks for the comment!
Can someone explain Qxd4?
A little more explanation. I played Nxc7# and the computer called it a blunder. It said best move was Rb1. I thought that move would just hang the pawn so I didnt even look at it.