[D]8/8/8/8/3k4/8/8/4K2R w - - 0 1
White should see a checkmate in a reasonable time and find shorter mates as search progresses.
I thought that it would be a good idea to confirm that my hashtable will take a beating, as well as my checkmate score system (in fact, I always used since I started in 2000 a system that resembles very much to what it was discussed in that thread by HG Muller). I do not have a link to it right now (I will try to post find it again).
Without a working hashtable, I do not think this is solvable. See that mate in 19 is found a ply 18! The reason I wanted to test this deserves another thread, my hashtable apparently was fine but I found a problem that the hashtable amplified it.
I did this test on my engine Gaviota on a Pentium 1.86 Ggz with 256 Mb of hash memory, and of course no endgame tablebases. I am glad to see that the checkmates are progressing nicely from mate in 19 to mate in 13, which is the correct solution. In less than 3 minutes it finds mate in 19, and it takes 6 hours (21884.8 seconds) to see mate in 13. Since I let it go over the weekend, at 35 hours reached ply 25 and stopped, because no mate under 13 can be found (which is correct). What I see though, is that the counter for nodes is overflowed and 32 bits are not enough anymore. Not a catastrophe, but I do not like it and I should change it.
How does your favorite engine do here?
Code: Select all
setboard 8/8/8/8/3k4/8/8/4K2R w - - 0 1
d
+-----------------+
| . . . . . . . . |
| . . . . . . . . |
| . . . . . . . . |
| . . . . . . . . | Castling:
| . . . k . . . . | ep: -
| . . . . . . . . |
| . . . . . . . . |
| . . . . K . . R | [White]
+-----------------+
analyze
[deleted short iterations]
444797 11 1.0 +3.56 Ke1-d2 Kd4-e4 Rh1-h4 Ke4-d5
Kd2-e3 Kd5-c5 Rh4-h5 Kc5-d6
Ke3-d4 Kd6-e6 Rh5-d5 Ke6-f6
Rd5-c5
643039 11 1.4 +3.56 Ke1-e2 Kd4-e4 Rh1-h5 Ke4-d4
Ke2-f3 Kd4-d3 Rh5-d5 Kd3-c3
Kf3-e3 Kc3-b4 Ke3-d4 Kb4-b3
657896 11: 1.4 +3.56 Ke1-e2 Kd4-e4 Rh1-h5 Ke4-d4
Ke2-f3 Kd4-d3 Rh5-d5 Kd3-c3
Kf3-e3 Kc3-b4 Ke3-d4 Kb4-b3
756463 12 1.6 +3.56 Ke1-e2 Kd4-e4 Rh1-h5 Ke4-d4
Ke2-f3 Kd4-d3 Rh5-d5 Kd3-c3
Kf3-e3 Kc3-c4 Ke3-e4 Kc4-b3
Rd5-c5
1013563 12: 2.1 +3.56 Ke1-e2 Kd4-e4 Rh1-h5 Ke4-d4
Ke2-f3 Kd4-d3 Rh5-d5 Kd3-c3
Kf3-e3 Kc3-c4 Ke3-e4 Kc4-b3
Rd5-c5
1189765 13 2.5 +3.56 Ke1-e2 Kd4-e4 Rh1-h5 Ke4-d4
Ke2-f3 Kd4-d3 Rh5-d5 Kd3-c3
Kf3-e3 Kc3-c4 Ke3-e4 Kc4-b3
Ke4-d4 Kb3-a3
1771051 13: 3.6 +3.56 Ke1-e2 Kd4-e4 Rh1-h5 Ke4-d4
Ke2-f3 Kd4-d3 Rh5-d5 Kd3-c3
Kf3-e3 Kc3-c4 Ke3-e4 Kc4-b3
Ke4-d4 Kb3-a3
2266965 14 4.6 +3.57 Ke1-e2 Kd4-e4 Rh1-h4 Ke4-d5
Ke2-d3 Kd5-e6 Rh4-h5 Ke6-f6
Kd3-e4 Kf6-f7 Ke4-e5 Kf7-g7
Rh5-h4 Kg7-g6 Rh4-g4 Kg6-h5
3172445 14: 6.4 +3.57 Ke1-e2 Kd4-e4 Rh1-h4 Ke4-d5
Ke2-d3 Kd5-e6 Rh4-h5 Ke6-f6
Kd3-e4 Kf6-f7 Ke4-e5 Kf7-g7
Rh5-h4 Kg7-g6 Rh4-g4 Kg6-h5
3855150 15 7.7 +3.57 Ke1-e2 Kd4-e4 Rh1-h4 Ke4-d5
Ke2-d3 Kd5-e6 Rh4-h5 Ke6-f6
Kd3-e4 Kf6-e6 Rh5-h6 Ke6-f7
Rh6-d6 Kf7-e7 Rd6-d5 Ke7-e8
Ke4-d4
5636330 15 11.2 +3.57 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Rd1-e1 Kf5-f6 Kf2-f3 Kf6-f5
Re1-e3 Kf5-f6 Kf3-g4 Kf6-f7
Kg4-g5 Kf7-g7 Re3-e7 Kg7-f8
5807032 15: 11.5 +3.57 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Rd1-e1 Kf5-f6 Kf2-f3 Kf6-f5
Re1-e3 Kf5-f6 Kf3-g4 Kf6-f7
Kg4-g5 Kf7-g7 Re3-e7 Kg7-f8
8374991 16 16.9 +3.58 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Rd1-e1 Kf5-f6 Kf2-f3 Kf6-f5
Re1-e2 Kf5-g5 Re2-e5 Kg5-f6
<-transp
10568671 16: 21.1 +3.58 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Rd1-e1 Kf5-f6 Kf2-f3 Kf6-f5
Re1-e2 Kf5-g5 Re2-e5 Kg5-f6
<-transp
13461671 17 26.8 +3.59 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Kf2-f3 Kf5-e5 Rd1-d2 Ke5-e6
Kf3-f4 Ke6-f7 Rd2-e2 Kf7-g6
Re2-e6 Kg6-g7 Kf4-g5 Kg7-f7
Re6-e3 Kf7-g7
18256299 17: 35.9 +3.59 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Kf2-f3 Kf5-e5 Rd1-d2 Ke5-e6
Kf3-f4 Ke6-f7 Rd2-e2 Kf7-g6
Re2-e6 Kg6-g7 Kf4-g5 Kg7-f7
Re6-e3 Kf7-g7
19150870 18 37.7 :-) Ke1-f2
71700881 18 158.1 +Mat_19 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Rd1-e1 Kf5-f4 Re1-e3 Kf4-g4
Re3-f3 Kg4-g5 Kf2-g3 Kg5-g6
Kg3-g4 Kg6-h7 Rf3-f7 Kh7-g6
Rf7-e7 Kg6-f6 Re7-e2 Kf6-g6
<-transp
356106348 18: 844.5 +Mat_19 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Rd1-e1 Kf5-f4 Re1-e3 Kf4-g4
Re3-f3 Kg4-g5 Kf2-g3 Kg5-g6
Kg3-g4 Kg6-h7 Rf3-f7 Kh7-g6
Rf7-e7 Kg6-f6 Re7-e2 Kf6-g6
<-transp
884211079 19 2275.8 +Mat_19 Ke1-f2 Kd4-c5 Rh1-h5 Kc5-c6
Kf2-f3 Kc6-b6 Kf3-e4 Kb6-c6
Ke4-d4 Kc6-d6 Rh5-d5 Kd6-e6
Kd4-e4 Ke6-f6 Ke4-f4 Kf6-e6
Rd5-d1 Ke6-f6 <-transp
1042648584 19 2699.1 +Mat_18 Ke1-d2 Kd4-e4 Rh1-h4 Ke4-e5
Kd2-d3 Ke5-d6 Rh4-d4 Kd6-e5
Kd3-e3 Ke5-f5 Rd4-e4 Kf5-g5
Re4-e5 Kg5-g6 Ke3-f4 Kg6-f6
Re5-e4 Kf6-g6 Re4-e6 Kg6-g7
Kf4-g5 Kg7-h7 Kg5-f6 Kh7-h8
<-transp
1132573694 19: 2940.4 +Mat_18 Ke1-d2 Kd4-e4 Rh1-h4 Ke4-e5
Kd2-d3 Ke5-d6 Rh4-d4 Kd6-e5
Kd3-e3 Ke5-f5 Rd4-e4 Kf5-g5
Re4-e5 Kg5-g6 Ke3-f4 Kg6-f6
Re5-e4 Kf6-g6 Re4-e6 Kg6-g7
Kf4-g5 Kg7-h7 Kg5-f6 Kh7-h8
<-transp
1372306279 20 3618.8 +Mat_18 Ke1-d2 Kd4-e4 Rh1-h4 Ke4-e5
Kd2-d3 Ke5-d6 Rh4-d4 Kd6-e5
Kd3-e3 Ke5-f5 Rd4-e4 Kf5-g5
Re4-e5 Kg5-g6 Ke3-f4 Kg6-f6
Re5-e4 Kf6-g6 Re4-e6 Kg6-g7
Kf4-g5 Kg7-h7 Kg5-f6 Kh7-h8
<-transp
1595375852 20 4243.8 +Mat_17 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Kf2-e3 Kf5-e5 Ke3-f3 Ke5-f5
Rd1-e1 Kf5-g5 Kf3-e4 Kg5-g6
Ke4-f4 Kg6-f6 Kf4-g4 Kf6-g6
Re1-e6 Kg6-g7 Kg4-g5 Kg7-h7
Kg5-f6 Kh7-h8 <-transp
1721458120 20: 4569.3 +Mat_17 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Kf2-e3 Kf5-e5 Ke3-f3 Ke5-f5
Rd1-e1 Kf5-g5 Kf3-e4 Kg5-g6
Ke4-f4 Kg6-f6 Kf4-g4 Kf6-g6
Re1-e6 Kg6-g7 Kg4-g5 Kg7-h7
Kg5-f6 Kh7-h8 <-transp
2120725316 21 5716.7 +Mat_17 Ke1-f2 Kd4-e4 Rh1-d1 Ke4-f5
Kf2-e3 Kf5-e5 Ke3-f3 Ke5-f5
Rd1-e1 Kf5-g5 Kf3-e4 Kg5-g6
Ke4-f4 Kg6-f6 Kf4-g4 Kf6-g6
Re1-e6 Kg6-g7 Kg4-g5 Kg7-h7
Kg5-f6 Kh7-h8 <-transp
2739744196 21 7398.9 +Mat_16 Ke1-e2 Kd4-e5 Ke2-e3 Ke5-d5
Rh1-d1 <-transp
2790699227 21: 7526.4 +Mat_16 Ke1-e2 Kd4-e5 Ke2-e3 Ke5-d5
Rh1-d1 <-transp
3006507371 22 8100.5 +Mat_15 Ke1-e2 Kd4-e5 Ke2-d3 Ke5-d5
Rh1-e1 Kd5-c5 Re1-e5 Kc5-c6
Kd3-c4 Kc6-d6 Re5-e4 Kd6-c6
Re4-d4 Kc6-b6 Rd4-d6 Kb6-b7
Kc4-d5 Kb7-c7 Kd5-c5 Kc7-b7
Rd6-d7 Kb7-c8 Kc5-c6 Kc8-b8
Rd7-d8 Kb8-a7 <-transp
4290869237 22: 11650.7 +Mat_15 Ke1-e2 Kd4-e5 Ke2-d3 Ke5-d5
Rh1-e1 Kd5-c5 Re1-e5 Kc5-c6
Kd3-c4 Kc6-d6 Re5-e4 Kd6-c6
Re4-d4 Kc6-b6 Rd4-d6 Kb6-b7
Kc4-d5 Kb7-c7 Kd5-c5 Kc7-b7
Rd6-d7 Kb7-c8 Kc5-c6 Kc8-b8
Rd7-d8 Kb8-a7 <-transp
532231690 23 13122.3 +Mat_15 Ke1-e2 Kd4-e5 Ke2-d3 Ke5-d5
Rh1-e1 Kd5-c5 Re1-e5 Kc5-c6
Kd3-c4 Kc6-d6 Re5-e4 Kd6-c6
Re4-d4 Kc6-b6 Rd4-d6 Kb6-b7
Kc4-d5 Kb7-c7 Kd5-c5 Kc7-b7
Rd6-d7 Kb7-c8 Kc5-c6 Kc8-b8
Rd7-d8 Kb8-a7 <-transp
3300095387 23 20804.8 +Mat_14 Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4
Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2
Ra4-f4 Kf2-g2 Kd3-e4 Kg2-g3
Ke4-e3 Kg3-g2 Rf4-g4 Kg2-h3
Ke3-f3 Kh3-h2 Rg4-h4 Kh2-g1
Rh4-h5 Kg1-f1 Rh5-h1
3365723746 23: 20952.0 +Mat_14 Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4
Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2
Ra4-f4 Kf2-g2 Kd3-e4 Kg2-g3
Ke4-e3 Kg3-g2 Rf4-g4 Kg2-h3
Ke3-f3 Kh3-h2 Rg4-h4 Kh2-g1
Rh4-h5 Kg1-f1 Rh5-h1
3771857860 24 21884.8 +Mat_13 Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4
Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2
Ra4-f4 Kf2-g2 Kd3-e2 Kg2-g3
Rf4-d4 Kg3-g2 Rd4-d3 Kg2-h1
Ke2-f2 Kh1-h2 Rd3-e3 Kh2-h1
Re3-h3
3678476938 24: 45674.7 +Mat_13 Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4
Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2
Ra4-f4 Kf2-g2 Kd3-e2 Kg2-g3
Rf4-d4 Kg3-g2 Rd4-d3 Kg2-h1
Ke2-f2 Kh1-h2 Rd3-e3 Kh2-h1
Re3-h3
493342729 25 48272.8 +Mat_13 Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4
Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2
Ra4-f4 Kf2-g2 Kd3-e2 Kg2-g3
Rf4-d4 Kg3-g2 Rd4-d3 Kg2-h1
Ke2-f2 Kh1-h2 Rd3-e3 Kh2-h1
Re3-h3
2513377439 25: 126951.3 +Mat_13 Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4
Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2
Ra4-f4 Kf2-g2 Kd3-e2 Kg2-g3
Rf4-d4 Kg3-g2 Rd4-d3 Kg2-h1
Ke2-f2 Kh1-h2 Rd3-e3 Kh2-h1
Re3-h3
Ply: 25
Rh1-h5 Kd4-e4 Ke1-e2 Ke4-f4 Ke2-d3 Kf4-g4 Rh5-b5 Kg4-f4
Rb5-a5 Kf4-f3 Ra5-a4 Kf3-f2 Ra4-f4 Kf2-g2 Kd3-e2 Kg2-g3
Rf4-d4 Kg3-g2 Rd4-d3 Kg2-h1 Ke2-f2 Kh1-h2 Rd3-e3 Kh2-h1
Re3-h3
Score: 125.29 (32075) Evals: -317153458 Time: 126951.3s nps: 19798 Q/all:
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