Excellent example of "horizon effect" in MMIV

[trontreez]

I will present to you an example of the "horizon effect" in a game I played recently against MMIV. I've also used the same tactic to win against Kaplan's Analyst C program. The tactic is very simple and is likely to come up in play on occasion. I would imagine that other programs from the same era have a similar flaw.

The tactic usually occurs in games where Black, the computer, plays Qb6 (or similar) attacking an unprotected b-pawn with it's Queen. White, the player, should ignore the threat to the b-pawn focussing on development and possible ways to trap the opponents queen. If the opponent does manage to save it's Queen the time wasted pinching pawns will allow for a promising attack.

The computer is not able to "see" that it's position, even if it is temporarily ahead in material, will eventually crumble. It's just too far over the horizon of the computer for it to realise that grabbing the pawn is not a good idea. I would guess that even most average club players would realise that pinching pawns early in the opening is asking for trouble.

It would be interesting if some of the program savvy guys here know what was done to address this issue for later programs?

The game as promised:

[Date "2016.09.28"]
[Result "1-0"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[White "trontreez"]
[WhiteElo "?"]
[Black "MMIV+HG400 LVL=3"]
[BlackElo "1804"]

1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Nf3 Ngf6 6.Ng3 e6 7.Bf4 Qb6

[fen]r1b1kb1r/pp1n1ppp/1qp1pn2/8/3P1B2/5NN1/PPP2PPP/R2QKB1R w KQkq - 0 8[/fen]

White's last move 7.Bf4 puts the MMIV out of book. MMIV plays 7...Qb6, a reasonable move, developing the Queen and attacking the b-pawn. White ignores the threat to the pawn and continues with development.

8.Bd3 Qxb2 9.O-O Nd5 10.Rb1 Qxa2 11.Bd2 b5 12.Ra1 Qb2 13.Qe2 Nc3 14.Bxc3 Qxc3 15.Rfb1 Ba3 16.Ne4 Qa5

[fen]r1b1k2r/p2n1ppp/2p1p3/qp6/3PN3/b2B1N2/2P1QPPP/RR4K1 w kq - 0 17 [/fen]

MMIV manages to save it's Queen with 15...Ba3 and is materially up by two pawns. Unfortunately with the lack of development of Black's pieces and exposed King in the centre the material advantage is irrelevant. White must still play with purpose and aggression however.

Here's how the attack plays out:

17.Nd6+ Kf8 18.Ng5 Nf6 19.Ndxf7 Rg8 20.Nd6 b4 21.Nxc8 Rxc8 22.Qxe6 Qc7

[fen]2r2kr1/p1q3pp/2p1Qn2/6N1/1p1P4/b2B4/2P2PPP/RR4K1 w - - 0 7[/fen]

Material equality has been restored and black has managed to defend against the imminent threat of mate. However the hopeless posting of the dark Bishop on a3, the rooks not connected and with the exposed nature of Black's King the result will surely end in white's favour. White wins the exchange shortly after and later another pawn and with it any chance of Black saving the game.

23.Qf5 Re8 24.Ne6+ Rxe6 25.Qxe6 Rh8 26.Re1 Qd7 27.Qxd7 Nxd7 28.Bc4 Nb6 29.Bb3 Nd7 30.Re6 c5 31.dxc5 Nxc5 32.Rc6 Nxb3 33.cxb3 Ke7 34.Rc7+ Kf6
1-0

[fen]7r/p1R3pp/5k2/8/1p6/bP6/5PPP/R5K1 w - - 0 1[/fen]

The final position! After Rxa7 white can simply protect his king against back rank threats and easily simplify, possibly by exchanging R for B+P.

In conclusion we see the power of hanging a pawn against an earlier, but still solid, computer opponent. This tactic seems to work especially well early in the game before the computer opponent has fully developed it's pieces and especially with the Queen knight and rook pawn when the human player has castled king side.

[Fernando]

I will present to you an example of the "horizon effect" in a game I played recently against MMIV. I've also used the same tactic to win against Kaplan's Analyst C program. The tactic is very simple and is likely to come up in play on occasion. I would imagine that other programs from the same era have a similar flaw.

The tactic usually occurs in games where Black, the computer, plays Qb6 (or similar) attacking an unprotected b-pawn with it's Queen. White, the player, should ignore the threat to the b-pawn focussing on development and possible ways to trap the opponents queen. If the opponent does manage to save it's Queen the time wasted pinching pawns will allow for a promising attack.

The computer is not able to "see" that it's position, even if it is temporarily ahead in material, will eventually crumble. It's just too far over the horizon of the computer for it to realise that grabbing the pawn is not a good idea. I would guess that even most average club players would realise that pinching pawns early in the opening is asking for trouble.

It would be interesting if some of the program savvy guys here know what was done to address this issue for later programs?

The game as promised:

[Date "2016.09.28"]
[Result "1-0"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[White "trontreez"]
[WhiteElo "?"]
[Black "MMIV+HG400 LVL=3"]
[BlackElo "1804"]

1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Nf3 Ngf6 6.Ng3 e6 7.Bf4 Qb6

[fen]r1b1kb1r/pp1n1ppp/1qp1pn2/8/3P1B2/5NN1/PPP2PPP/R2QKB1R w KQkq - 0 8[/fen]

White's last move 7.Bf4 puts the MMIV out of book. MMIV plays 7...Qb6, a reasonable move, developing the Queen and attacking the b-pawn. White ignores the threat to the pawn and continues with development.

8.Bd3 Qxb2 9.O-O Nd5 10.Rb1 Qxa2 11.Bd2 b5 12.Ra1 Qb2 13.Qe2 Nc3 14.Bxc3 Qxc3 15.Rfb1 Ba3 16.Ne4 Qa5

[fen]r1b1k2r/p2n1ppp/2p1p3/qp6/3PN3/b2B1N2/2P1QPPP/RR4K1 w kq - 0 17 [/fen]

MMIV manages to save it's Queen with 15...Ba3 and is materially up by two pawns. Unfortunately with the lack of development of Black's pieces and exposed King in the centre the material advantage is irrelevant. White must still play with purpose and aggression however.

Here's how the attack plays out:

17.Nd6+ Kf8 18.Ng5 Nf6 19.Ndxf7 Rg8 20.Nd6 b4 21.Nxc8 Rxc8 22.Qxe6 Qc7

[fen]2r2kr1/p1q3pp/2p1Qn2/6N1/1p1P4/b2B4/2P2PPP/RR4K1 w - - 0 7[/fen]

Material equality has been restored and black has managed to defend against the imminent threat of mate. However the hopeless posting of the dark Bishop on a3, the rooks not connected and with the exposed nature of Black's King the result will surely end in white's favour. White wins the exchange shortly after and later another pawn and with it any chance of Black saving the game.

23.Qf5 Re8 24.Ne6+ Rxe6 25.Qxe6 Rh8 26.Re1 Qd7 27.Qxd7 Nxd7 28.Bc4 Nb6 29.Bb3 Nd7 30.Re6 c5 31.dxc5 Nxc5 32.Rc6 Nxb3 33.cxb3 Ke7 34.Rc7+ Kf6
1-0

[fen]7r/p1R3pp/5k2/8/1p6/bP6/5PPP/R5K1 w - - 0 1[/fen]

The final position! After Rxa7 white can simply protect his king against back rank threats and easily simplify, possibly by exchanging R for B+P.

In conclusion we see the power of hanging a pawn against an earlier, but still solid, computer opponent. This tactic seems to work especially well early in the game before the computer opponent has fully developed it's pieces and especially with the Queen knight and rook pawn when the human player has castled king side.

Good, commons sense game, which is always difficult to have and play. Anybody or almost knows that about pawns that poison the eater, but no many knows HOW to get advantage of that and the lose of a pawn at last is just the lose of the pawn.

[trontreez]

Would you believe last night, the very next night, I played against the Analyst C and the opportunity to sacrifice my pawn on b2 arose again. Unfortunately I wasn't able to get the points this time and probably had other winning methods after Analyst played 12...Qb5. Credit must be given to Kaplan as Analyst really fought hard, like a dog, when on the back foot. I probably should have taken draw by repetition when I had the chance.

[Date "2016.09.29"]
[Result "*"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[White "trontreez"]
[Black "Analyst C 10Mhz(60s/move)"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.Re1 Bg4 6.c3 Bxf3 7.Qxf3 Qd7 8.d4 a6 9.Bxc6 Qxc6 10.Bg5 Be7 11.Nd2 O-O-O 12.d5 Qb6 13.c4 Qxb2 14.a4 Rd7 15.Reb1 Qc2 16.Rb3 Nxd5 17.Bxe7 Nxe7 18.Qe3 Nc6 19.Rc3 Qb2 20.Rb1 Qa2


[fen]2kr3r/1pp1bppp/pq1p1n2/3Pp1B1/2P1P3/5Q2/PP1N1PPP/R3R1K1 w KQkq - 0 1[/fen]

Analyst "C" plays 13... Qxb2 and white should win with good play.

[fen]2k4r/1ppr1ppp/p1np4/4p3/P1P1P3/2R1Q3/q2N1PPP/1R4K1 w KQkq - 0 1[/fen]

White can opt to take the draw by attacking the black Queen with Ra3 Qc2 Rc3 Qa2 Ra3 or look for more and go for the kill.