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Subject: Re: Pro Deo bug or is it an issue with the Fritz GUI?

Author: Ed Schröder

Date: 15:46:22 08/18/04

Go up one level in this thread


On August 18, 2004 at 09:44:46, Albert Silver wrote:

Albert,

I can reproduce both moves. The key to that is to clear the hash table first. In
ChessPartner that's easy: F4 -> Clear Hash table. Under Fritz and co use the
engine parameter:

  [Clear Hash Table = Always]     * Always | Never | PB only

My best,

Ed

======================


>I've been having fun playing around with the settings, but have noticed some
>really strange things happening in the automated matches played in the Fritz
>GUI.
>
>I looked over the games, enjoyed Pro Deo's victories, and checked the losses of
>course. In one game, I saw Pro Deo had a huge edge, according to both it and
>Junior 8, yet lost. I was intrigued. Had they both seriously misevaluated the
>position or did PD blunder horribly?
>
>Example:
>
>[D]4r1k1/1p4pp/p7/2QNpb2/4q3/1P6/1PP5/1K1R4 b - - 0 31
>
>The game is hardly over, but there isn't an engine that doesn't think Black has
>a huge edge. Adn why not? Black *has* a huge edge. Black didn't blunder here,
>but already some odd things appear. Pro Deo played 31...b5 here (with -1.91 for
>black and 12 plies depth, and Junior expected 31...Qe2. So I run Pro Deo, with
>my settings, and see its analysis.
>
>Analysis by Pro Deo 1.0:
>
>31...Qe2
>  -+  (-1.67)   Depth: 1   00:00:00
>31...Qg2
>  -+  (-1.76)   Depth: 1   00:00:00
>31...Qg2 32.Qc7
>  -+  (-1.64)   Depth: 2   00:00:00
>31...Qg2 32.Ne3 Qf3
>  -+  (-1.66)   Depth: 3   00:00:00
>31...Qg2 32.Ne3 Qf3 33.Rg1
>  -+  (-1.60)   Depth: 4   00:00:00
>31...Bg4
>  -+  (-1.60)   Depth: 4   00:00:00
>31...Bg4 32.Qg1 Rf8 33.Rd3
>  -+  (-1.80)   Depth: 4   00:00:00
>31...Bg4 32.Rg1 Kh8 33.Ne3 Bf3
>  -+  (-1.55)   Depth: 5   00:00:00
>31...Kh8 32.Rf1 Rd8 33.Ne3 Be6 34.Rf8+
>  -+  (-1.73)   Depth: 5   00:00:00
>31...Kh8 32.Ne3 b5 33.Rg1 Qf4 34.Qc7
>  -+  (-1.68)   Depth: 6   00:00:00  78kN
>31...Kh8 32.Ne3 Be6 33.Qb6 Qc6 34.Qb4
>  -+  (-1.68)   Depth: 7   00:00:01  220kN
>31...Kh8 32.Ne3 Be6 33.Qb6 Qc6 34.Qb4 Qf3 35.Qb6
>  -+  (-1.70)   Depth: 8   00:00:01  657kN
>31...Kh8 32.Ne3 Be6 33.Qb6 Qc6 34.Qb4 b5 35.Qh4 Rf8
>  -+  (-1.73)   Depth: 9   00:00:02  1509kN
>31...Kh8 32.Ne3 b5 33.Qe7 Bg6 34.Rf1 Kg8 35.Qg5 Qd4 36.Ka1
>  -+  (-1.69)   Depth: 10   00:00:04  4017kN
>31...Qe2 32.Rg1 Kh8 33.Qc7 Rg8 34.Nb6 Qd2 35.Rh1
>  -+  (-1.73)   Depth: 10   00:00:06  5415kN
>31...Qe2 32.Rg1 Kh8 33.Qc7 Bg6 34.Rc1
>  -+  (-1.78)   Depth: 11   00:00:12  11377kN
>31...Qe2 32.Rc1 Kh8 33.Ne7
>  -+  (-1.68)   Depth: 12   00:00:23  22071kN
>31...Kh8 32.Ne7 h6 33.Rc1 Bh7 34.Qd6
>  -+  (-1.71)   Depth: 12   00:00:35  34791kN
>31...Kh8 32.Ne3 Be6 33.Qb6 g6
>  -+  (-1.73)   Depth: 13   00:01:41  97962kN
>
>No 31...b5 in sight, and mind you this is single CPU with no permanent brain.
>Hmmmm!
>
>I pinpoint the losing blunder, squandering the draw to clear loss, and no, I
>don't have any odd contempt values on:
>
>[D]4r2k/4N1pp/p7/1p2R3/8/PP6/1Kb5/8 b - - 0 38
>
>In this position, White is threatening Ng6+ picking up the rook. Black must keep
>the bishop on the diagonal so as to meet Ng6 with Bxg6 protecting the rook.
>White can therefore draw by attacking the bishop with 38.Kb2 as here, 38...Bd3
>only move, 39.Kc3 Bb1 40.Kb2 and a repetition is in order. Instead I see
>38...g6?? with -0.23 at 14 plies, 39.Kxc2 Kg7 40.Nf5+ Kf8 41.Rxe8 and things
>went downhill with white winning the endgame. I honestly don't care how the
>endgame went since when I ask Pro Deo (same settings) what it thinks of the
>position after 38.Kb2 it says:
>
>38...Bxb3 39.Kxb3
>  =  (0.04)   Depth: 1   00:00:00
>38...Rxe7 39.Rxe7
>  ³  (-0.31)   Depth: 1   00:00:01
>38...Bf5 39.Rxf5 Rxe7
>  -+  (-1.94)   Depth: 1   00:00:01
>38...Bg6
>  -+  (-2.04)   Depth: 1   00:00:01
>38...Bg6 39.Nxg6+ hxg6 40.Rxe8+ Kh7
>  +-  (2.99)   Depth: 2   00:00:01
>38...Bd1 39.Ng6+ hxg6 40.Rxe8+ Kh7
>  =  (0.08)   Depth: 2   00:00:01
>38...Bf5 39.Rxf5 Rxe7
>  -+  (-1.94)   Depth: 2   00:00:01
>38...Bf5 39.Rxf5 g5
>  ²  (0.38)   Depth: 3   00:00:01
>38...Bd1 39.Ng6+ hxg6 40.Rxe8+
>  =  (0.08)   Depth: 3   00:00:01
>38...Bd3 39.Kc3 Rd8
>  -+  (-1.94)   Depth: 3   00:00:01
>38...Bd3 39.Kc3 Rd8 40.Nd5
>  -+  (-1.89)   Depth: 4   00:00:01
>38...Bd3 39.Kc3 Rd8 40.Nc6 Rc8 41.Kxd3
>  -+  (-1.86)   Depth: 5   00:00:01
>38...Bd3 39.Kc3 Rd8 40.Nc6 Rc8 41.Kxd3 Rxc6
>  -+  (-1.86)   Depth: 6   00:00:01  13kN
>38...Bd3 39.Kc3 Rd8 40.Nc6 b4+ 41.Nxb4 Bb5
>  µ  (-0.87)   Depth: 7   00:00:01  25kN
>38...Bd3 39.Kc3 Rd8 40.Nc6 b4+ 41.Nxb4 Bb5 42.Nd5
>  µ  (-0.89)   Depth: 8   00:00:01  45kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 9   00:00:02  119kN
>38...Bxb3 39.Kxb3 Rf8 40.Nd5 Rf3+ 41.Kb4 g6 42.Re6 Rf5
>  =  (0.00)   Depth: 9   00:00:02  369kN
>38...Bxb3 39.Kxb3 Rf8 40.Re6 Rf3+ 41.Kb4 Rf4+ 42.Kc5 Ra4 43.Nf5 h5 44.Re8+ Kh7
>  =  (0.00)   Depth: 10   00:00:02  730kN
>38...Bxb3 39.Kxb3 Rf8 40.Re6 Rf6 41.Rxf6 gxf6 42.Kb4 Kg7 43.Kc5 h5 44.Nf5+ Kg6
>  =  (0.00)   Depth: 11   00:00:03  2473kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 11   00:00:04  2811kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 12   00:00:04  3593kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 13   00:00:07  6793kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 14   00:00:13  12772kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 15   00:00:29  31455kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 16   00:01:09  76135kN
>38...Bd3 39.Kc3 Bb1 40.Kb2 Bd3
>  =  (0.00)   Depth: 17   00:03:18  224497kN
>
>So how the heck did 38...g6 get played?? Ed? Anyone?
>
>My settings have been on my Athlon 2400XP+ with 256 MB ram:
>
>Nunn I set, 30 mins + 2 sec increment, 64 MB hash for Junior 8 and w6 setting
>(60 MB hash) for Pro Deo, permanent brain off.
>
>                                      Albert



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