Game Amateur 2.80 - Ikarus 0.18 : an interesting test positi

[Olivier Deville]

Geschrieben von:/Posted by: Olivier Deville at 06 August 2004 11:31:30:

A game from ChessWar B, round 1, time control 40/40.

fen=8/8/8/8/1RP5/PP2k3/r7/5K2w
After 51" Amateur played 61.a4?? and could not avoid the draw (61...Kf3 62.Kg1 Kg3, etc).
61.c5 for example would have won.
Olivier



ChessWar + AEGT

[Will Singleton]

Geschrieben von:/Posted by: Will Singleton at 06 August 2004 17:30:24:
Als Antwort auf:/In reply to: Game Amateur 2.80 - Ikarus 0.18 : an interesting test position geschrieben von:/posted by: Olivier Deville at 06 August 2004 11:31:30:

A game from ChessWar B, round 1, time control 40/40.
After 51" Amateur played 61.a4?? and could not avoid the draw (61...Kf3 62.Kg1 Kg3, etc).
61.c5 for example would have won.
Olivier

Pretty amazing position. At ply 20, the pv switches from:
19 552 11335 56093089 c5 Kf3 Ke1 Ke3 Kd1 Kd3 Rc4 Rxa3 c6
20 447 18473 91015016 c5 Kf3 Ke1 Ke3 Kd1 Kd3 Kc1 Rc2 Kb1 Rxc5 a4
Apparently, Amateur didn't want to give up the a-pawn after Rc4, switching to Kc1, which gives up the c-pawn instead. That causes a slight score drop, then a switch in the root to a4. It sees that a4 draws almost immediately, but fails to select a new move in time. I don't know why it took so long, I'll have to look at that. The move it eventually likes, Rb6, would probably win as well.
Some strong programs fail to see the problem with a4 for a long time, so at least Amateur could see the draw. Yace is particularily good here, discarding a4 after only a few seconds.


Amateur 2.80, p4 2.8ghz:
15 585 1409 6988691  c5 Rxa3 c6 Ra7 Rb7 Ra6 c7 Kf3 Ke1 Ke3 Kd1 
16 598 2194 10898680 c5 Rxa3 c6 Kf3 Kg1 Kg3 Ra4 Rxb3 Kf1 Kf3
17 598 3192 15949128 c5 Rxa3 c6 Kf3 Ke1 Ke3 Kd1 Kd3 Rc4 Ra8 c7 Rg8 
18 599 4940 24520164 c5 Rxa3 c6 Kf3 Ke1 Ke3 Kd1 Kd3 Rc4 Ra8 c7 Rg8
19 552 11335 56093089 c5 Kf3 Ke1 Ke3 Kd1 Kd3 Rc4 Rxa3 c6 
20 447 18473 91015016 c5 Kf3 Ke1 Ke3 Kd1 Kd3 Kc1 Rc2 Kb1 Rxc5 a4
17 447 18473 91015017 c5 
17 552 18574 91517161 a4 
18 552 18717 92238483 a4 
19 0 18832 92875729   a4 Kf3 Ke1 Ke3 Kd1 Kd3 Kc1 Kc3 Kb1 Rf2 Rb7 Rf1 Ka2 Rf2 Ka3 Rf1 Ka2 
17 0 18832 92875730   a4 
17 470 26232 128446271 Kg1 Kf3 Rb7 Rxa3 b4 Ra1 Kh2 Rc1 Rf7 Kg4 Rc7 Rc2 Kg1 Kg3 Kf1 Kf3 Rf7 Ke4 c5 Kd5 Rd7 Ke5 
17 537 29695 145338069 Rb6 Rxa3 c5 Kd4 
18 542 37342 182818790 Rb6 Rxa3 c5 Ra1 Kg2 Kd4 b4 
19 546 53935 264153650 Rb6 Rxa3 c5 Kd4 c6 Ke5 b4 Kd6 b5 Ra7 Rb8 Kc7 Rf8 
20 546 68860 338700001 Rb6 Rxa3 c5 Kd4 c6 Ke5 b4 Kd6 b5 Ra7 Rb8 Kc7 Rf8