Seperating the men from the toys - test position

[AdminX]

in this case toys = chess programs
So easy for humans to spot.

[d] 8/4p3/rr1p1p2/bkp1PPp1/1p1P2Pp/p1PK3P/PPB5/8 w - -

I assume you are looking for 1. c4+ Kc6 2. d5+ K-any 3. d5 and then putting the B on b3 to lock things up? Crafty will play this instantly, but it has no clue it is a draw because it will take a ton of move to either reach the 50 move counter or cause black to repeat...

This one is even better (found by Shredder instantly)



29/44 0:24 -0.29 1.Ba4+ Kxa4 2.b3+ Kb5 3.c4+ Kc6
4.d5+ Kb7 5.e6 (77.504.863) 3179 SB:8

best move: Bc2-a4 time: 0:29.047 min n/s: 3.164.246 CPU 396.0% n/s(1CPU): 799.052 nodes: 91.810.596 SB: 11

It locks up everything 'forced' without the Bishop!

BYe
Ingo

This combo is 9 plies deep. I wonder why Shredder sees it right away and others don't?

[Laurens Winkelhagen]

Probably because of what was mentioned earlier: Most engines need to look 50 extra moves for a draw, whist shredder seems to have specialized code to recognize this (pawn + B/Q) pattern and it's implications.

[Paloma]

I don't think so.
e.g. 1.c4 Kc6 2.d5+ Kc7 3.b3 dxe5! 4.Ke3 Rd6 5.Be4 Ra8
6.Kd2 Rad8 7.Ke3 Rxd5 8.cxd5 c4 9.bxc4 b3 10.Bb1 bxa2 11.Bxa2 Kd6 -+

Tested with Shredder11

Regards

[Dirt]

Shredder is the only one that gets this from my tests. Interestingly even Shredder 9 finds Ba4 instantly with a -0.4 evaluation!

Programs that failed were

Rybka 3
HIARCS 12
Fritz 10 & 11
Zappa M II
Junior 10

note that that doesn't seem to be the _only_ way to force a draw, just "a way"...

No one else seems to agree with you. Maybe you could go a little deeper than the first move in these other drawing lines you see.

[bob]

Shredder is the only one that gets this from my tests. Interestingly even Shredder 9 finds Ba4 instantly with a -0.4 evaluation!

Programs that failed were

Rybka 3
HIARCS 12
Fritz 10 & 11
Zappa M II
Junior 10

note that that doesn't seem to be the _only_ way to force a draw, just "a way"...

No one else seems to agree with you. Maybe you could go a little deeper than the first move in these other drawing lines you see.

First, I didn't just look at the first move. Second I was not using a computer. I did not spend an hour studying this. This position is not new and has been published multiple times in the last 30+ years as a "computer-busting" move showing how computers fail in something that is easy for a human to see.

It's certainly possible my quick analysis was wrong. But it was based on a lot more than just letting a computer choose the first move. The other flavor of this position is to go ahead and lock the pawns, except give black a rook that can be captured by a white pawn. Computers will take it in general, and use that newly available pawn lever to break the position open for the other rook, while a human would not take the rook, ever.

[bob]

in this case toys = chess programs
So easy for humans to spot.

[d] 8/4p3/rr1p1p2/bkp1PPp1/1p1P2Pp/p1PK3P/PPB5/8 w - -

I assume you are looking for 1. c4+ Kc6 2. d5+ K-any 3. d5 and then putting the B on b3 to lock things up? Crafty will play this instantly, but it has no clue it is a draw because it will take a ton of move to either reach the 50 move counter or cause black to repeat...

Also looks like c4, d5 and b3 will work too...

How can White play both 2.d5+ and 3.d5?
To me it looks like there is only 1 way to draw which is the line 1.Ba4+ etc.Any thing else will alow the pawn structure to be opened up with either axb2, dxe5, fxe5.

3. d5 was a typo, and it was not really intended as the 3rd move, but just a move that gets played as soon as possible. You can't play it at move 3 because of black's axb2 which becomes a problem. I agree a human will play the bishop move quickly. I knew about the move before the position was given as this position has been published many times in the past. My comment was mainly "is that the _only_ way to draw, or just the _obvious_ way. I didn't spend any great amount of time and could easily have made a mistake.