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Subject: Re: interesting Phalanx move

Author: Will Singleton

Date: 09:46:00 03/09/02

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On March 09, 2002 at 11:05:45, Jon Dart wrote:

>Phalanx seems to have an amazing talent for finding "quiet" but deadly moves.
>Here is one example:
>
>[D] rn3rk1/pbp2p1p/1p2pp2/8/3PP3/q1P1QN2/P1P3PP/1K1R1B1R w - -
>
>Phalanx played Rd3 and the game continued c5 Nd2 Ba6 1-0 (White will play c4 and
>Black will have to sac the Queen to avoid the deadly Qh6).
>
>There's probably a better defense but Rd3 is good. Arasan will play Rd3 after
>about 2 minutes on an Athlon 1.3Ghz but doesn't give it a high + score.
>
>I couldn't get Crafty 18.10 to play it all. Crafty "hangs" for a long time
>resolving the move d5. Here is the search output:
>
>              clearing hash tables
>              time surplus   0.00  time limit 20:00 (20:00)
>         nss  depth   time  score   variation (1)
>                7     0.97   0.00   1. Nd2 Qd6 2. e5 fxe5 3. Qg5+ Kh8 4.
>                                    Qf6+ Kg8 5. Qg5+
>                7->   1.00   0.00   1. Nd2 Qd6 2. e5 fxe5 3. Qg5+ Kh8 4.
>                                    Qf6+ Kg8 5. Qg5+
>                8     1.75   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ <HT>
>                8->   1.89   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ <HT>
>                9     3.18   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ Kh8 5. Qf6+
>                9->   3.64   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ Kh8 5. Qf6+
>               10     8.14   0.01   1. Nd2 Kh8 2. Bc4 Nd7 3. Qg3 Rac8 4.
>                                    Rhf1 c5 5. d5 Rce8
>               10->  22.20   0.01   1. Nd2 Kh8 2. Bc4 Nd7 3. Qg3 Rac8 4.
>                                    Rhf1 c5 5. d5 Rce8
>               11    34.17   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ Kh8 5. Qf6+
>               11->  45.47   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ Kh8 5. Qf6+
>               12     1:09   0.00   1. Nd2 Kh8 2. Qf4 Qxc3 3. Qxf6+ Kg8
>                                    4. Qg5+ Kh8 5. Qf6+
>               12    10:01   0.06   1. d5 Qe7 2. Nd4 Kh8 3. dxe6 fxe6 4.
>                                    Bc4 Re8 5. Qg3 Bc8 6. Nb5 Na6 7. Rhf1
>               12->  10:36   0.06   1. d5 Qe7 2. Nd4 Kh8 3. dxe6 fxe6 4.
>                                    Bc4 Re8 5. Qg3 Bc8 6. Nb5 Na6 7. Rhf1
>
>The weird thing is, if I move Rd3 and then have Crafty search the resulting
>position from the Black side, I get over +1 for White right away:
>
>              clearing hash tables
>              time surplus   0.00  time limit 20:00 (20:00)
>         nss  depth   time  score   variation (1)
>                6     0.43   1.18   1. ... Qa4 2. Qf4 c5 3. Rd2 Qc6 4.
>                                    Qxf6 <HT>
>                6     0.69   1.05   1. ... Ba6 2. c4 Qe7 3. Rb3 c5 4. Qf4
>                                    cxd4 5. Nxd4
>                6->   0.72   1.05   1. ... Ba6 2. c4 Qe7 3. Rb3 c5 4. Qf4
>                                    cxd4 5. Nxd4
>                7     0.98   1.36   1. ... Ba6 2. Rd1 Nc6 3. Nd2 b5 4.
>                                    Qg3+ Kh8 5. Qf3 Kg8
>                7     1.33   1.14   1. ... Qd6 2. Nd2 Ba6 3. c4 c5 4. d5
>                                    Nd7 5. dxe6 Qxe6
>                7->   1.96   1.14   1. ... Qd6 2. Nd2 Ba6 3. c4 c5 4. d5
>                                    Nd7 5. dxe6 Qxe6
>                8     2.11   1.31   1. ... Qd6 2. Nd2 Ba6 3. c4 Nc6 4.
>                                    Qf2 Qb4+ 5. Rb3 Qd6
>                8->   6.54   1.31   1. ... Qd6 2. Nd2 Ba6 3. c4 Nc6 4.
>                                    Qf2 Qb4+ 5. Rb3 Qd6
>                9     7.22   1.37   1. ... Qd6 2. Nd2 Ba6 3. c4 Nd7 4.
>                                    Qh6 Kh8 5. Be2 Rad8
>                9->  15.49   1.37   1. ... Qd6 2. Nd2 Ba6 3. c4 Nd7 4.
>                                    Qh6 Kh8 5. Be2 Rad8
>               10    17.50     --   1. ... Qd6
>               10    25.18   2.41   1. ... Qd6 2. e5 Qd5 3. exf6 Qb5+ 4.
>                                    Kc1 Qf5 5. Qh6 Qg6 6. Qh4 Qe4
>               10    25.44     ++   1. ... Qe7!!
>               10    33.78   1.62   1. ... Qe7 2. Nd2 Kh8 3. Qh6 Rg8 4.
>                                    Rh3 Rg7 5. Rh4 c5 6. dxc5 bxc5 7. Nc4
>               10    42.62   1.35   1. ... Ba6 2. Rd1 Nd7 3. Nh4 Rac8 4.
>                                    Qg3+ Kh8 5. Qh3 Bb7 6. Bb5 Rcd8 7.
>                                    Qf3
>               10->  59.27   1.35   1. ... Ba6 2. Rd1 Nd7 3. Nh4 Rac8 4.
>                                    Qg3+ Kh8 5. Qh3 Bb7 6. Bb5 Rcd8 7.
>                                    Qf3
>               11     1:13   1.47   1. ... Ba6 2. c4 Qa4 3. Ra3 Qb4+ 4.
>                                    Rb3 Qd6 5. e5 Qe7 6. Qf4 fxe5 7. Nxe5
>                                    Nd7
>               11->   2:07   1.47   1. ... Ba6 2. c4 Qa4 3. Ra3 Qb4+ 4.
>                                    Rb3 Qd6 5. e5 Qe7 6. Qf4 fxe5 7. Nxe5
>                                    Nd7
>               12     2:32   1.40   1. ... Ba6 2. c4 Qa4 3. Ra3 Qb4+ 4.
>                                    Rb3 Qe7 5. Nd2 e5 6. Qh6 Kh8 <HT>
>
>Note Crafty prefers Ba6 as Black's response, not c5 as in the game.
>
>--Jon


Yace plays Rd3 in about the same time as Arasan, given the cpu difference (amd
1.6 ghz).  However, it appears that your c5 is a mistake, that either Ba6 or Nd7
is fine, as the queen can escape.  Crafty's +1 eval isn't justified, as Qe7 is
better than Qa4.


5 35 12 54027 t  1.Nd2 c5 2.Nc4 Qa4 3.Be2 {0}
5 35 12 54570 .  1.Nd2 c5 2.Nc4 Qa4 3.Be2 {0}
6 37 16 81544 t  1.Nd2 c5 2.Qg3+ Kh8 3.Qc7 Bc6H 4.Qe7H {0}
6 37 20 104683 .  1.Nd2 c5 2.Qg3+ Kh8 3.Qc7 Bc6 4.Qe7 {0}
7 45 37 220585 t  1.Nd2 Rc8 2.Bb5 Qa5 3.Qd3 Nc6 4.Rhf1 {0}
7 45 52 322377 .  1.Nd2 Rc8 2.Bb5 Qa5 3.Qd3 Nc6 4.Rhf1 {0}
8 39 103 702463 t  1.Nd2 Kh8 2.Nc4 Qa4 3.Qh6H Nd7H 4.Bd3H Kg8H {0}
8 39 191 1294327 .  1.Nd2 Kh8 2.Nc4 Qa4 3.Qh6 Nd7 4.Bd3 Kg8 {0}
9 44 597 3882800 t  1.Nd2 Rc8 2.Bb5 a6 3.Nc4 Qe7 4.Ba4H Nd7H 5.Rhf1H {0}
9 44 852 5593087 .  1.Nd2 Rc8 2.Bb5 a6 3.Nc4 Qe7 4.Ba4 Nd7 5.Rhf1 {0}
10 38 1520 10203696 t  1.Nd2 Kh8 2.Bb5 a6 3.Nc4 Qe7 4.Ba4 Rg8 5.g3 Nd7 {0}
10 39 4748 32456192 t+ 1.d5 exd5 2.exd5 Rd8 3.Bc4 c6 4.d6 Rxd6 5.Rxd6 Kh8 6.Qe8+
Kg7 {420}
10 40 7434 49674805 t  1.d5 Qc5 2.Qxc5 bxc5 3.Bc4 exd5 4.exd5 Nd7 5.Rhe1 Rab8
6.Ka1 Rfd8 {HT} {0}
10 41 8543 57071236 t+ 1.Rd3 Nd7 2.Nd2 Ba6 3.Qg3+ Kh8 4.Rf3 Bxf1 5.Rhxf1 Qxc3
6.Rxc3 Rg8 {HT} {921}
10 48 9466 63024562 t  1.Rd3 Ba6 2.c4 Qa5 3.Ra3 Qh5 4.Qf4 Qg6 5.g3 Bb7 {0}
10 48 9902 65921831 .  1.Rd3 Ba6 2.c4 Qa5 3.Ra3 Qh5 4.Qf4 Qg6 5.g3 Bb7 {0}
11 52 11699 78461248 t  1.Rd3 Ba6 2.c4 Qa4 3.Ra3 Qb4+ 4.Rb3 Qd6H 5.Qh6H c5H {HT}
{0}
11 52 16560 113146094 .  1.Rd3 Ba6 2.c4 Qa4 3.Ra3 Qb4+ 4.Rb3 Qd6 5.Qh6 c5 {HT}
{0}
12 66 21307 147003367 t  1.Rd3 Ba6 2.c4 Qa4 3.Ra3 Qb4+ 4.Rb3 Qd6 5.Qh6 e5 6.d5
Nd7 7.Be2 {0}
12 66 30944 216230640 .  1.Rd3 Ba6 2.c4 Qa4 3.Ra3 Qb4+ 4.Rb3 Qd6 5.Qh6 e5 6.d5
Nd7 7.Be2 {0}
13 74 53194 374478364 t  1.Rd3 Nd7 2.Nd2 Kh8 3.Qf4 Qd6 4.Qh6 Rg8 5.Rh3 Rg7 6.Bb5
c6 {HT} {0}



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