Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Question for Prof. Hyatt

Author: Robert Hyatt

Date: 16:13:42 02/25/06

Go up one level in this thread


That looks strange to me.  Here is Crafty on my 750mhz laptop, giving all depth
outputs:

              depth   time  score   variation (1)
                1     0.00  -0.60   1. ... Rb7
                1->   0.00  -0.60   1. ... Rb7
                2     0.00  -0.42   1. ... Rb7 2. e4
                2     0.00  -0.48   1. ... c3 2. bxc3 Rxc3
                2->   0.00  -0.48   1. ... c3 2. bxc3 Rxc3
                3     0.01  -0.48   1. ... c3 2. bxc3 Rxc3
                3     0.01  -0.72   1. ... Rb7 2. e4 Rg7
                3->   0.01  -0.72   1. ... Rb7 2. e4 Rg7
                4     0.01  -0.40   1. ... Rb7 2. e4 fxe4+ 3. Kxe4 Rd7
                4     0.01     -1   1. ... c3!!
                4     0.02  -1.26   1. ... c3 2. bxc3 Rxc3 3. Ra2
                4->   0.02  -1.26   1. ... c3 2. bxc3 Rxc3 3. Ra2
                5     0.02  -1.56   1. ... c3 2. bxc3 Rxc3 3. Ra2 Rc2
                5->   0.02  -1.56   1. ... c3 2. bxc3 Rxc3 3. Ra2 Rc2
                6     0.03  -1.49   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3
                6->   0.03  -1.49   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3
                7     0.04  -1.51   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4
                7->   0.04  -1.51   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4
                8     0.06  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
                8->   0.11  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
                9     0.13  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
                9->   0.19  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
               10     0.24  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
               10->   0.52  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
               11     0.58  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
               11->   1.13  -1.58   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3
               12     1.24     -1   1. ... c3!!
               12     1.41  -2.10   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3 a3
               12->   2.70  -2.10   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. h4 Rb3 6. Rxd3 Rxd3
                                    7. Kxd3 a3
               13     3.22     -1   1. ... c3!!
               13     3.55  -2.41   1. ... c3 2. bxc3 Rxc3 3. Rb2 Rxa3
                                    4. Rb6+ Ke7 5. Rb7+ Ke6 6. Rb6+ Kd5
                                    7. Rb7 Kd6 8. Rb4 Kc5 9. Rd4 h6 <HT>
               13->   6.29  -2.41   1. ... c3 2. bxc3 Rxc3 3. Rb2 Rxa3
                                    4. Rb6+ Ke7 5. Rb7+ Ke6 6. Rb6+ Kd5
                                    7. Rb7 Kd6 8. Rb4 Kc5 9. Rd4 h6 <HT>
               14     7.95  -2.44   1. ... c3 2. bxc3 Rxc3 3. Rb2 Rxa3
                                    4. Rb6+ Kf7 5. Rb7+ Kg6 6. Rb6+ Kh5
                                    7. Rb7 d2 8. Rxh7+ Kg6 9. Rd7 Ra2 10.
                                    Rd6+ Kg7 11. h4
               14->  15.19  -2.44   1. ... c3 2. bxc3 Rxc3 3. Rb2 Rxa3
                                    4. Rb6+ Kf7 5. Rb7+ Kg6 6. Rb6+ Kh5
                                    7. Rb7 d2 8. Rxh7+ Kg6 9. Rd7 Ra2 10.
                                    Rd6+ Kg7 11. h4
               15    19.49  -2.51   1. ... c3 2. bxc3 Rxc3 3. e4 fxe4+
                                    4. Kxe4 Rxa3 5. Rb2 Rb3 6. Rxb3 axb3
                                    7. Kxd3 Kf5 8. Kc3 h6 9. Kxb3 Kxf4
               15    40.19     -1   1. ... Rxb2!!
               15    42.07     -3   1. ... Rxb2!!
               15    47.85  -4.13   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Kc5 6. Rb8 c2 7.
                                    Rc8+ Kb5 8. Kg3 d2 <HT>
               15->  54.75  -4.13   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Kc5 6. Rb8 c2 7.
                                    Rc8+ Kb5 8. Kg3 d2 <HT>
              time=56.42  mat=0  n=20333227  fh=89%  nps=360K
              ext-> chk=898427 1rep=18873 mate=193
              predicted=0  nodes=20333227  evals=11783895  50move=0
              endgame tablebase-> probes=0  hits=0


What looks so wrong is that you like Rxb2 at very early depths.  Here is the
search output if crafty only considers Rxb2 at the root, no other moves allowed:
              depth   time  score   variation (1)
                1     0.00   1.86   1. ... Rxb2 2. Rxb2
                1->   0.00   1.86   1. ... Rxb2 2. Rxb2
                2     0.01   1.86   1. ... Rxb2 2. Rxb2
                2->   0.01   1.86   1. ... Rxb2 2. Rxb2
                3     0.01     -1   1. ... Rxb2!!
                3     0.01   0.70   1. ... Rxb2 2. Rxb2 c3
                3->   0.02   0.70   1. ... Rxb2 2. Rxb2 c3
                4     0.02   1.00   1. ... Rxb2 2. Rxb2 c3 3. Rb7
                4->   0.02   1.00   1. ... Rxb2 2. Rxb2 c3 3. Rb7
                5     0.02   1.00   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kf7
                                    4. Rb7+ Kg6
                5->   0.02   1.00   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kf7
                                    4. Rb7+ Kg6
                6     0.02   1.18   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kf7
                                    4. Rb7+ Kg6 5. e4
                6->   0.02   1.18   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kf7
                                    4. Rb7+ Kg6 5. e4
                7     0.02     -1   1. ... Rxb2!!
                7     0.04   0.62   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kg7
                                    4. Rb7+ Kg6 5. e4 c2 <HT>
                7->   0.04   0.62   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kg7
                                    4. Rb7+ Kg6 5. e4 c2 <HT>
                8     0.06   0.68   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kg7
                                    4. Rb7+ Kg6 5. e4 fxe4+ 6. Kxe4 c2
                8->   0.06   0.68   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Kg7
                                    4. Rb7+ Kg6 5. e4 fxe4+ 6. Kxe4 c2
                9     0.13     -1   1. ... Rxb2!!
                9     0.16   0.18   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rf7 c2 6. Rf6+ Kd7 7.
                                    Rf7+ Ke6
                9->   0.18   0.18   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rf7 c2 6. Rf6+ Kd7 7.
                                    Rf7+ Ke6
               10     0.26  -0.01   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Ke7
               10->   0.27  -0.01   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Ke7
               11     0.38  -0.01   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Ke7
               11->   0.39  -0.01   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Ke7
               12     0.85  -0.01   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Ke7
               12->   0.86  -0.01   1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
                                    4. Rb7+ Kd6 5. Rb6+ Ke7
              time=0.88  mat=0  n=242418  fh=95%  nps=275K
              ext-> chk=12385 1rep=324 mate=0



So early on, Rxb2 looks very bad for black (good for white) until it thinks it
finds a repetition...

So the question has to be, why does your program like Rxb2 so early???  It drops
a rook outright.



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.