How will chess engines evaluate this position

[Pio]

Hi!

I played this game a short while ago.

[pgn]1. e4 e5 2. d4 exd4 3. c3 dxc3 4. Bc4 cxb2 5. Bxb2 b5 6. Bxf7+ Kxf7 7. Qd5+ Ke8 8. Qxa8 Nc6 9. Nf3 Bb4+ 10. Nfd2 Nf6 11. O-O Kf7 12. a4 bxa4 13. Rxa4 Qe7 14. e5 Nd5 15. Rxa7 Nb6 0-1[/pgn]

I do not know anyone playing my pawn b7-b5 move or if it was good. The idea was either to trap his queen on a8 (which also happened) or trying to attack his king's side where is the only safe place for his king. I would be very happy if you could run your chess engines to analyze the following two FEN positions

[d]rnbqkbnr/p1pp1ppp/8/1p6/2B1P3/8/PB3PPP/RN1QK1NR w KQkq b6

[d]Q1bqkbnr/p1pp2pp/2n5/1p6/4P3/8/PB3PPP/RN2K1NR w KQ -

[elcabesa]

my engine gives this line for the first position:

info depth 21 seldepth 40 score cp 107 nodes 19039020 time 106258 nps 179180 pv c4f7 e8f7 d1d5 f7e8 d5a8 b8c6 g1f3 g8f6 b1d2 c8a6 a8d8 e8d8 e1g1 f8b4 a2a3 b4e7 f1c1 h8g8 f3d4 c6d4 b2d4 a6b7 e4e5 f6e4 d2e4 b7e4

so it looks right to capture in f7.

the second position give me this eval:
info depth 21 seldepth 38 score cp 110 lowerbound nodes 8766166 time 72165 nps 121478 pv g1f3 g8f6 b1d2 c8a6 a8d8 e8d8 e1g1 f8b4 a2a3 b4e7 f1c1 h8g8 f3d4 c6d4 b2d4 a6b7 e4e5 f6e4 d2e4 b7e4 d4a7

so it looks right Nf3

[Pio]

Hi Marco!

Thank you so much for your analysis. What I think is strange is the bishop move c8 to a6. Why exchange queens when you might exchange your rook later with the queen. Maybe the engine is right but I am still not convinced that white is any better off than black.

If you look at the position you could see that white queen cannot move to any square without being caught. In the same way black cannot move his queen away before his rook can protect his bishop and then move bishop c8 to a6 to exchange black's rook with white's queen. The big question is if black has the time to manuever his rook into the right position before white has exchanged knight with black knight. I think it is a really difficult position to asses both for humans and computers. I guess your engine is not evaluating mobility with respect to SEE because then it would see that white queen cannot move to any square without being caught or maybe/probably I am completely wrong and cannot look deep enough to see that white queen eventually could escape

Thanks!!!

[zamar]

Hi Marco!

Thank you so much for your analysis. What I think is strange is the bishop move c8 to a6. Why exchange queens when you might exchange your rook later with the queen. Maybe the engine is right but I am still not convinced that white is any better off than black.

If you look at the position you could see that white queen cannot move to any square without being caught. In the same way black cannot move his queen away before his rook can protect his bishop and then move bishop c8 to a6 to exchange black's rook with white's queen. The big question is if black has the time to manuever his rook into the right position before white has exchanged knight with black knight. I think it is a really difficult position to asses both for humans and computers. I guess your engine is not evaluating mobility with respect to SEE because then it would see that white queen cannot move to any square without being caught or maybe/probably I am completely wrong and cannot look deep enough to see that white queen eventually could escape

Thanks!!!

Why not to download an engine to try it yourself?

Stockfish quickly demonstrates that 12. a4 was a mistake, 12.e5! Nd5 e6! and queen escapes...

[zamar]

Hi Marco!

Thank you so much for your analysis. What I think is strange is the bishop move c8 to a6. Why exchange queens when you might exchange your rook later with the queen. Maybe the engine is right but I am still not convinced that white is any better off than black.

If you look at the position you could see that white queen cannot move to any square without being caught. In the same way black cannot move his queen away before his rook can protect his bishop and then move bishop c8 to a6 to exchange black's rook with white's queen. The big question is if black has the time to manuever his rook into the right position before white has exchanged knight with black knight. I think it is a really difficult position to asses both for humans and computers. I guess your engine is not evaluating mobility with respect to SEE because then it would see that white queen cannot move to any square without being caught or maybe/probably I am completely wrong and cannot look deep enough to see that white queen eventually could escape

Thanks!!!

Why not to download an engine to try it yourself?

Stockfish quickly demonstrates that 12. a4 was a mistake, 12.e5! Nd5 e6! and queen escapes...

Sorry, I misread the game. The initial mistake was 10. Nfd2?. 10. Nbd2! is a much better move. Then planning 0-0 and e5.

[Pio]

Hi Joona!

You are right that I could downlowd a free chess engine and analyze the position by myself but I would love to compare different chess engines analysis.

I am not a good chess player but I cannot see how white queen could escape that easily. Could you please post the pgn of Stockfish's analysis.

Thanks!!!

[Kyodai]

I just found one game with this 5.-b5 - from 1878 Boistertre-Mabillis, Paris
This game went 6. Bb3 Bb7 etc