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Subject: Re: Is your engine too materialistic?

Author: Robert Hyatt

Date: 19:26:05 07/12/03

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On July 12, 2003 at 18:57:18, John Merlino wrote:

>In a recent game that I played on ICC with CM9000 (default personality) against
>Tinker (a very good amateur program that plays with a nice style), Tinker played
>several moves that would lead me to believe that it is too materialistic in its
>evaluation. Here are a few positions to test if your engine might have the same
>problems.
>
>In this first position, Tinker is up two pawns and is probably winning:
>
>[D]r1b1k2r/p1p2ppp/2p5/4P3/2P2qn1/3B4/1B2Q1PP/R3K2R b KQkq - 0 15

Crafty, on my PIII/750 laptop, rejects Nxh2 very quickly:

                5->   0.29  -2.31   1. ... Nxh2 2. Qf2 Qxf2+ 3. Kxf2 Ng4+
                                    4. Kf3 h6 5. Rhd1
                6     0.42     --   1. ... Nxh2
                6     0.49  -1.59   1. ... Nxh2 2. e6 Qg3+ 3. Kd1 f6 4.
                                    Qh5+ g6 5. Bxg6+ Qxg6 6. Rxh2 Qxh5+
                                    7. Rxh5 Bxe6 8. Bxf6
                6     0.80  -1.84   1. ... Be6 2. Be4 O-O 3. g3 Qe3 4.
                                    Qxe3 Nxe3 5. Bxc6
                6     0.90  -1.97   1. ... O-O 2. g3 Qg5 3. Qe4 Qh6 4.
                                    Bd4
                6->   1.03  -1.97   1. ... O-O 2. g3 Qg5 3. Qe4 Qh6 4.
                                    Bd4
                7     1.25  -2.01   1. ... O-O 2. g3 Qg5 3. O-O a5 4. Qe4
                                    Qe3+ 5. Qxe3 Nxe3
                7->   1.81  -2.01   1. ... O-O 2. g3 Qg5 3. O-O a5 4. Qe4
                                    Qe3+ 5. Qxe3 Nxe3
                8     2.27  -1.98   1. ... O-O 2. g3 Qg5 3. O-O Rd8 4.
                                    Rf4 a5 5. Ra4
                8->   3.73  -1.98   1. ... O-O 2. g3 Qg5 3. O-O Rd8 4.
                                    Rf4 a5 5. Ra4
                9     5.82  -1.99   1. ... O-O 2. g3 Qg5 3. O-O Rd8 4.
                                    Rf4 a5 5. h3 Nh6

It sticks with O-O thru depth 12 where I stopped it.

>
>However, it plays 15...Nxh2? Before this move, CM thought it was down about 1.0;
>after it thought it was up about 0.4.
>
>A few moves later and now Tinker is up FOUR pawns (although the knight on h2
>will soon be lost), although CM's eval only favored Black by about 1.0.
>
>[D]r3k2r/p1p2ppp/2p1b3/8/2P4q/3B2P1/1B2Q2n/R2K3R b kq - 0 18

Crafty favors black with an eval of -.64:

                8->   1.21  -0.64   1. ... Qxg3 2. Be5 Qg5 3. Qxh2 Bg4+
                                    4. Kc2 f6 5. Bxc7 Qc5 6. Bxh7 Qxc4+
                9     2.56  -0.65   1. ... Qxg3 2. Be5 Qg5 3. Qxh2 h5 4.
                                    Re1 O-O 5. Rg1 Bg4+ 6. Kc2
                9->   2.86  -0.65   1. ... Qxg3 2. Be5 Qg5 3. Qxh2 h5 4.
                                    Re1 O-O 5. Rg1 Bg4+ 6. Kc2
               10     6.73  -0.61   1. ... Qxg3 2. Be5 Qg5 3. Bxh2 Qe7
                                    4. Bg1 h6 5. Bxa7 O-O 6. Bf5
               10->   8.06  -0.61   1. ... Qxg3 2. Be5 Qg5 3. Bxh2 Qe7
                                    4. Bg1 h6 5. Bxa7 O-O 6. Bf5

>
>Tinker now plays 18...Qxg3?, and the eval jumps up to about 0.5 in White's
>favor.
>
>Finally, this position. Material is "even", but White has a clear advantage.
>CM9000 scored this position about 1.7 in White's favor.
>
>[D]r3k1r1/5p1p/2p1b3/8/q1P5/p1BB1Q2/8/R1K4R b q - 0 27                7->   3.73   2.01   1. ... O-O-O 2. Bc2 Qxc4 3. Rxa3 Bd5
                                    4. Qf5+ Be6 5. Qxh7
                8     4.18   2.02   1. ... O-O-O 2. Bc2 Qxc4 3. Rxa3 Bg4
                                    4. Bf5+ Bxf5 5. Qxf5+ Qe6 6. Qxh7
                8->   9.53   2.02   1. ... O-O-O 2. Bc2 Qxc4 3. Rxa3 Bg4
                                    4. Bf5+ Bxf5 5. Qxf5+ Qe6 6. Qxh7
                9    13.74   2.24   1. ... O-O-O 2. Bc2 Qxc4 3. Rxa3 h5
                                    4. Qe3 c5 5. Ra8+ Kb7 6. Rxd8 Rxd8
                                    7. Rxh5
                9->  42.09   2.24   1. ... O-O-O 2. Bc2 Qxc4 3. Rxa3 h5
                                    4. Qe3 c5 5. Ra8+ Kb7 6. Rxd8 Rxd8
                                    7. Rxh5
               10    49.07   2.32   1. ... O-O-O 2. Bc2 Qxc4 3. Rxa3 Bg4
                                    4. Qe3 h5 5. Ra8+ Kd7 6. Qa7+ Kd6 7.
                                    Rxd8+ Rxd8 8. Qe3 <HT>


Crafty likes O-O-O but thinks black is lost:


>
>Tinker plays 27...Bxc4? which loses outright. After this move, CM gives an eval
>of 6.5 for White.
>
>How do your engines do at avoiding these moves?
>
>Finally, just for fun, here's a position from a few moves later:
>
>[D]r1k3r1/5p1p/2p2Q2/8/2q5/p1B5/8/R1K1R3 w - - 0 31
>
>In this position, on my P4-2.4, Chessmaster announces Mate in 14 in 0:15, and
>upgrades it to Mate in 13 after 0:23.

Crafty finds the right move quickly, but it takes a long time on my laptop
to find the mate.  My dual xeon might do it in under a minute.


>
>jm



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