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Subject: Re: Johan de Koning, clearing hash between moves

Author: chandler yergin

Date: 07:25:04 01/30/06

Go up one level in this thread


On January 30, 2006 at 10:16:52, K. Burcham wrote:

>
>
>Is this an example why Johan de Koning clears hash between moves?
>Qb4 is a blunder. Rybka played Qb4 in the game, instead of the safer Qb5. If I
>play through the moves at depth 11 with hash info, Rybka will blunder (first
>example).

Check your analysis.
46...Qb5 47.Rf3 Bxh6 48.e5 Qc6 49.exf6+ Kd6 50.Qb8+ Qc7 51.Qxc7+
  ²  (0.27)   Depth: 12   00:00:25  1637kN
It took 25 seconds for Rybka to find 46....Qb5!
In the game it had to play the best move found at the time it had to move.
Which was 46....Qb4
OK?
Chan

>
>If I clear the hash and play from this position with empty hash, Rybka does not
>show blunder Qb4 in eval (second example).
>
>Nichtda,F - Qwertyui,R, 3m + 0s, rated blitz 2006
>2Q5/1p2kb2/1q3p1P/2p2P2/3pP3/4b2R/8/3B3K b - - 0 1
>
>Rybka 1.0 Beta 32-bit:
>
>46...Qb4 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 7   00:00:00
>46...Qb4 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 8   00:00:00
>46...Qb4 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 9   00:00:00
>46...Qb4 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 10   00:00:00
>46...Qb4 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 11   00:00:01
>46...Qb4 47.Qc7+ Ke8 48.Qg3 Qb1 49.Qg4 Bxh6 50.Rxh6 Ke7 51.Rh8
>  +-  (3.17)   Depth: 12   00:00:03  286kN
>46...Qb5 47.Rf3 Bxh6 48.e5 Qc6 49.exf6+ Kd6 50.Qb8+ Qc7 51.Qxc7+
>  ²  (0.27)   Depth: 12   00:00:25  1637kN
>46...Qb5 47.Rf3 Bxh6 48.e5 Bd5 49.Qc7+ Qd7 50.exf6+ Ke8 51.f7+
>  ²  (0.53)   Depth: 13   00:00:48  3012kN
>46...Qb5 47.Rf3 Bxh6 48.Qc7+ Qd7 49.Qxc5+ Qd6 50.Qb5 b6 51.Rh3
>  ²  (0.63)   Depth: 14   00:01:17  4956kN
>
>
>46...Qb5 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 7   00:00:00  9kN
>46...Qb5 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 8   00:00:00  19kN
>46...Qb5 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 9   00:00:00  43kN
>46...Qb5 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 10   00:00:01  96kN
>46...Qb5 47.Qc7+ Ke8 48.Qc8+ Ke7 49.Qc7+ Ke8 50.Qc8+ Ke7 51.Qc7+
>  =  (0.00)   Depth: 11   00:00:03  252kN
>46...Qb5 47.Rf3 Bxh6 48.e5 fxe5 49.Qc7+ Kf8 50.Qd8+ Qe8 51.Qd6+
>  =  (0.15)   Depth: 12   00:00:14  937kN
>46...Qb5 47.Rf3 Bxh6 48.e5 Bd5 49.Qc7+ Qd7 50.exf6+ Ke8 51.f7+
>  ²  (0.53)   Depth: 13   00:00:43  2605kN
>46...Qb5 47.Rf3 Bxh6 48.Qc7+ Qd7 49.Qxc5+ Qd6 50.Qb5 b6 51.Rh3
>  ±  (0.75)   Depth: 14   00:01:17  4809kN
>46...Qb5 47.Qc7+ Ke8 48.Rf3 Qb1 49.Qc8+ Ke7 50.Qxc5+ Kd7 51.Qc2
>  ±  (0.88)   Depth: 15   00:02:59  11338kN



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