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Subject: Re: A comparison of engines' evaluation

Author: Christopher A. Morgan

Date: 06:52:47 01/01/03

Go up one level in this thread



Shredder 7 and Fritz 8 evaluate the position nearly the same at -0.47 and -0.44,
respectively, while Junior 7 evaluates position on my computer at -0.05.

Shredder 7 did not change analysis between 3 seconds and 3:35, analysis clip,
last part, follows (Athlon 750, 96MB hash):

New game
r1bqk1nr/pppp1ppp/2n5/2b1p3/1PB1P3/5N2/P1PP1PPP/RNBQK2R b - - 0 1

Analysis by Shredder 7:

1...Bxb4 2.c3
  3  (-0.39)   Depth: 11/16   00:00:01  20kN
1...Bxb4 2.c3
  3  (-0.39)   Depth: 12/18   00:00:01  40kN
1...Bxb4 2.c3
  3  (-0.39)   Depth: 13/16   00:00:02  120kN
1...Bxb4 2.c3
  3  (-0.39)   Depth: 14/17   00:00:03  204kN
1...Bxb4 2.c3 Ba5 3.Qb3 Qe7 4.d3 d6 5.Be3 Bb6 6.Bxb6 axb6 7.Bxf7+ Qxf7 8.Qe6+
Bxe6
  3  (-0.47)   Depth: 15/36   00:03:35  25453kN

Fritz 8 (Version 8.0.0.8) did not change analysis between 24 seconds and 1:33.
Last part of analysis clip follows:

New game
r1bqk1nr/pppp1ppp/2n5/2b1p3/1PB1P3/5N2/P1PP1PPP/RNBQK2R b - - 0 1

Analysis by Fritz 8:

1...Bxb4 2.c3 Be7 3.Kf1 Kf8 4.d4 d6 5.Be3 exd4 6.cxd4 Nf6
  3  (-0.28)   Depth: 10/26   00:00:02  620kN
1...Bxb4 2.c3 Be7 3.Kf1 Kf8 4.d4 d6 5.Nbd2 Nf6 6.Qb3 Qe8
  3  (-0.34)   Depth: 11/32   00:00:08  2228kN
1...Bxb4 2.c3 Be7 3.Kf1 Nf6 4.d4 exd4 5.e5 Ng4 6.cxd4 Kf8 7.Kg1
  3  (-0.28)   Depth: 12/33   00:00:24  7283kN
1...Bxb4 2.c3 Be7 3.Kf1 Kf8 4.d4 exd4 5.cxd4 Na5 6.Bd3 d5 7.Nbd2 dxe4 8.Nxe4 Nf6
9.Nc5
  3  (-0.50)   Depth: 13/40   00:01:33  29561kN
1...Bxb4 2.c3 Be7 3.Kf1 Kf8 4.d4 exd4 5.cxd4 Na5 6.Bd3 d5 7.Nbd2 dxe4 8.Nxe4
  3  (-0.44)   Depth: 14/42   00:02:47  53870kN


For comparison purposes I also include Junior 7:


New game
r1bqk1nr/pppp1ppp/2n5/2b1p3/1PB1P3/5N2/P1PP1PPP/RNBQK2R b - - 0 1

Analysis by Junior 7:

1...Bxb4 2.c3 Bc5 3.Ba3 Qe7 4.Qa4 Nf6 5.Ng5 Rf8 6.Ke2
  =  (-0.08)   Depth: 12   00:00:02  970kN
1...Bxb4 2.c3 Bf8 3.Na3 a6 4.h4 b5 5.Bb3 Bc5 6.Ke2
  =  (-0.08)   Depth: 15   00:00:26  14317kN
1...Bxb4 2.c3 Bd6 3.d4 Qf6 4.Kf1 Nh6 5.Bg5 Qg6 6.Nbd2 f6 7.Bh4
  =  (-0.05)   Depth: 17   00:02:14  70668kN


On January 01, 2003 at 08:48:39, Omid David Tabibi wrote:

>[D] r1bqk1nr/pppp1ppp/2n5/2b1p3/1PB1P3/5N2/P1PP1PPP/RNBQK2R b KQkq b3 0 4
>
>The Evans Gambit, arising after 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4, is a good
>example of positional material sacrifice. By sacrificing his b pawn, white gains
>a number if precious tempos, thus seizing the opening initiative. While the 4.b4
>gambit might not be better than the other 4th moves here, it usually reaches a
>balanced position in which white has enough compensation for the sacrificed
>pawn.
>
>Now let us see how the top engines evaluate this position. There is not much
>tactics involved here, so this gives us a good opportunity to compare the
>programs' evaluation (their chess knowledge).
>
>In the table below, the evaluation of each engine is recorded after 1 minute
>analysis (since the evaluation is largely positional, no significant score
>change was noticed from one ply to another, so most probably even deeper
>searches will not change the result):
>
>
>Engine            Score
>------            -----
>Junior 7           0.06
>Fritz 7           -0.41
>Shredder 6.02     -0.33
>Chess Tiger 14    -0.82  (Gambit Tiger 2 also produced the same score)
>Hiarcs 8          -0.84
>Crafty 19.1       -0.81
>
>
>Interesting points:
>
>    - Junior 7 was the only program who evaluated the position realistically.
>
>    - Gambit Tiger 2 which is tuned for sacrificial play, did not evaluate
>      the position differently from Chess Tiger 14.
>
>    - Hiarcs 8 which is said to incorporate the most chess knowledge, displays
>      the least chess understanding in this position! (Conclusion: more chess
>      knowledge does not necessarily mean better evaluation.)
>
>Omid.
>
>P.S. An analysis of Fritz 8 and Shredder 7 will be appreciated.



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