reckless forgot a mate score after a long search

[Uri Blass]

reckless already showed a mate score at depths 21-22 but forgot about it at depth 23-25

[d]3qk3/8/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1


Reckless 0.10.0_generic:
1/1 00:00 256 16k +6.01 a2-a3
2/2 00:00 352 20k +6.14 a2-a3
3/3 00:00 484 26k +6.23 a2-a3
4/4 00:00 1k 25k +7.25 Ng1-h3
5/9 00:00 7k 58k +7.26 c2-c3 Qd8-h4 Qd1-a4+ Qh4xa4
6/7 00:00 15k 104k +7.15 c2-c3 Qd8-b8 Qd1-a4+ Ke8-f7 Qa4-b3+ Qb8xb3
7/14 00:00 35k 193k +7.34 c2-c3 Ke8-e7 Qd1-b3 Ke7-f6 Qb3-f7+ Kf6xf7 Ng1-f3 Kf7-f6
8/19 00:00 86k 366k +7.41 c2-c3 Ke8-f7 Qd1-a4 Qd8-e7 f2-f4 Qe7-b7 Qa4-d7+ Qb7xd7
9/12 00:00 92k 385k +7.40 c2-c3 Ke8-f7 Qd1-a4 Qd8-e7 f2-f4 Qe7-h4+ g2-g3 Qh4-d8 Qa4-b3+ Qd8-d5
10/18 00:00 170k 606k +7.37 c2-c4 Qd8-d4 Qd1-b3 Ke8-f7 c4-c5+ Kf7-f6 Ng1-f3 Qd4-e4 Qb3-c3+ Kf6-f7
11/26 00:00 899k 1,551k +7.94 Nb1-c3 Ke8-f7 Nc3-d5 Qd8xd5 c2-c4 Qd5-d4 Qd1-b3 Kf7-g6 Qb3-e3 Kg6-h7 c4-c5 Qd4xe3
12/20 00:00 1,297k 1,804k +8.22 c2-c4 Qd8-d4 Nb1-c3 Qd4xc4 Qd1-b3 Qc4xb3 a2xb3 Ke8-d7 Ra1-a8 Kd7-c7 e2-e4 Kc7-b7 Bf1-a6+ Kb7-b6 Nc3-d5+ Kb6-c5
13/20 00:00 1,496k 1,865k +8.19 c2-c4 Qd8-c7 Nb1-c3 Ke8-d7 Qd1-a4+ Qc7-c6 Qa4xc6+ Kd7xc6 Ng1-f3 Kc6-c7
14/22 00:00 1,693k 1,917k +8.27 c2-c4 Qd8-c7 Nb1-c3 Ke8-d7 Qd1-a4+ Kd7-d8 Qa4-b3 Qc7-c6 Qb3-b8+ Kd8-e7 Nc3-d5+ Ke7-f7 Qb8-c7+ Qc6xc7
15/32 00:01 2,382k 2,071k +8.46 c2-c4 Qd8-c7 Nb1-c3 Qc7-c5 Nc3-d5 Ke8-f7 Qd1-b3 Qc5-c6 Qb3-f3+ Kf7-g8 Qf3-g3+ Kg8-f7 Qg3-c7+ Qc6xc7
16/27 00:01 3,900k 2,270k +8.64 c2-c4 Qd8-c7 Nb1-c3 Qc7-c5 Qd1-b3 Qc5-d6 Nc3-d5 Ke8-f7 Qb3-h3 Qd6-d8 Qh3-g3 Kf7-e8 f2-f4 Ke8-f7 f4-f5 Qd8-b6 Nd5xb6
17/30 00:03 8,649k 2,667k +9.01 c2-c4 Qd8-c7 Qd1-b3 Qc7-c5 Nb1-c3 Ke8-f7 Nc3-d5 Qc5-f8 f2-f4 Kf7-g8 Qb3-h3 Qf8-g7 f4-f5 Qg7-f7 Qh3-g3+ Kg8-h8
18/38 00:06 18,603k 2,900k +9.77 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-d4 f2-f4 Qd4xf4 e2-e3 Qf4-h4+ g2-g3 Qh4-h5 Qb3-b8+ Ke8-e7 Qb8-b7+ Ke7-f6
19/45 00:10 29,673k 2,926k +10.06 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-f7 f2-f4 Qf7-f5 Nc3-d5 Ke8-f8 Qb3-b8+ Kf8-g7 Qb8-c7+ Qf5-f7 Qc7-d8 Qf7-f5 Qd8-e7+ Qf5-f7 Qe7-e5+ Kg7-g8 f4-f5 Kg8-h7 Qe5-d6 Kh7-g8 Qd6-g3+ Qf7-g7 Qg3-b8+ Qg7-f8 Qb8-b7 Qf8-f7 Qb7-c8+ Qf7-f8
20/45 00:15 45,732k 2,959k +10.42 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-f7 f2-f4 Ke8-f8 Nc3-d5 Kf8-g7 f4-f5 Qf7xf5 Qb3-c3+ Kg7-f7 Qc3-c7+ Kf7-e6 Qc7-c6+ Ke6-f7 Qc6-d6 Qf5-e6 Qd6-f4+ Kf7-g7 b2-b4 Qe6xd5 Bc1-b2+ Kg7-g8 Qf4-f6 Qd5-b7 Qf6-h8+ Kg8-f7 Qh8-g7+ Kf7-e8
21/52+ 00:37 105,771k 2,788k +11.44 c2-c4
21/52+ 16:18 1,891,992k 1,933k +12.84 c2-c4
21/127+ 32:26 3,774,041k 1,938k +29.75 c2-c4
21/127- 36:07 4,242,827k 1,957k +19.41 c2-c4 Qd8-d4
21/127- 47:41 5,618,212k 1,964k +24.58 c2-c4
21/127- 1:39:35 11,261,391k 1,885k +71.17 c2-c4
21/127- 1:40:17 11,351,035k 1,886k +29.55 c2-c4 Qd8-h4
21/127- 1:40:21 11,357,927k 1,886k +47.18 c2-c4
21/127 1:44:45 11,943,168k 1,900k +M20 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-f7 Nc3-d5 Ke8-f8 f2-f4 Kf8-g7 f4-f5 Qf7xf5 Qb3-g3+ Kg7-f8 Qg3-d6+ Kf8-g7 Qd6-e7+ Qf5-f7 Qe7xf7+ Kg7xf7 Ng1-f3 Kf7-e6 e2-e4 Ke6-d6 d2-d4 Kd6-c6 Nf3-e5+ Kc6-b7 Bc1-h6 Kb7-a8 Ra1-c1 Ka8-b7 Rc1-c7+ Kb7-a8 Bh6-f4 Ka8-b8 Ne5-c6+ Kb8-a8 Nd5-b6+
22/38+ 1:44:45 11,943,171k 1,900k +95.92 c2-c4
22/118 1:44:49 11,952,598k 1,900k +M19 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-f7 Nc3-d5 Ke8-f8 f2-f4 Qf7-e8 Qb3-b7 Qe8-f7 Qb7-b8+ Kf8-g7 Qb8-e5+ Kg7-f8 f4-f5 Qf7-e8 Qe5-d6+ Kf8-g7 Qd6-g3+ Kg7-f7 Qg3-c7+ Kf7-f8 b2-b3 Qe8-f7 Qc7-d8+ Qf7-e8 Bc1-a3+ Kf8-f7 Qd8-c7+ Qe8-d7 Qc7xd7+ Kf7-g8 Nd5-f6+ Kg8-h8 Qd7-h7+
23/48 1:44:49 11,952,601k 1,900k +57.26 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-f7 Nc3-d5 Ke8-f8 f2-f4 Qf7-d7 f4-f5 Qd7-c6 Qb3-a3+ Kf8-g8 Qa3-g3+ Kg8-f7 Qg3-e5 Qc6-h6 Qe5-e7+ Kf7-g8 Qe7-e8+ Kg8-g7 f5-f6+ Kg7-h7 Qe8-e4+ Qh6-g6
24/53 1:44:49 11,952,611k 1,900k +69.30 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-f7 Nc3-d5 Ke8-f8 f2-f4 Qf7-d7 f4-f5 Qd7-c6 Qb3-a3+ Kf8-g8 Qa3-g3+ Kg8-f7 Qg3-e5 Qc6-h6 Qe5-e7+ Kf7-g8 Qe7-e8+ Kg8-g7 f5-f6+ Kg7-h7 Qe8-f7+ Kh7-h8 Qf7-e7 Qh6-h4+ g2-g3 Qh4-h7 Qe7-e8+ Qh7-g8 f6-f7 Qg8xe8 f7xe8Q+ Kh8-g7 Qe8-d7+ Kg7-h6 d2-d4+ Kh6-g6 Qd7-d6+ Kg6-g7 Qd6-e7+ Kg7-g6 Qe7-g5+ Kg6-f7
25/127 1:44:56 11,967,186k 1,901k +69.41 c2-c4 Qd8-h4 Nb1-c3 Qh4xc4 Qd1-b3 Qc4-c8 Nc3-d5 Ke8-f7 f2-f4 Kf7-g7 Qb3-g3+ Kg7-f7 Qg3-g5 Qc8-e6 Qg5-h5+ Kf7-g7 f4-f5 Qe6-e5 Qh5-g5+ Kg7-f7 Qg5-d8 Qe5-e4 Qd8-d7+ Kf7-f8 Qd7-d6+ Kf8-g8 Qd6-e6+ Qe4xe6 f5xe6 Kg8-f8 e6-e7+ Kf8-e8 Ng1-f3 Ke8-f7 e7-e8Q+ Kf7xe8

[Jouni]

Analysis by Reckless 0.9.0:
...
1.e4 Ke7 2.Nc3 Qg8 3.Qh5 Qe6 4.d4 Kf8 5.Bh6+ Ke7 6.Qc5+ Kf6 7.Qf8+ Qf7 8.Bg5+ Kxg5 9.Qxf7 Kh6 10.g3 Kg5 11.Qg7+ Kh5 12.Be2#
+- (#12) Depth: 27/25 00:00:17 90324kN

[Paloma]

Analysis by Stockfish 11 64 BMI2:

1.e4 Qc8 2.Qh5+ Ke7 3.Bb5 Qe6 4.Nc3 Qf7 5.Qh8 Qf8 6.Qe5+ Kf7 7.Bc4+ Kg6 8.d4 Qf7 9.Qg5+ Kh7 10.Bxf7 Kh8 11.Qh6#
Depth: 78/25 00:02:25 2954MN

[Jouni]

Analysis by Stockfish 18:

1.e4 Qg5 2.d4 Qg6 3.Qf3 Qf7 4.Bb5+ Ke7 5.Bg5+ Kf8 6.Bh6+ Ke7 7.Qg3 Qf8 8.Bxf8+ Kxf8 9.Qg6 Ke7 10.Qf5 Kd6 11.Qd7#
+- (#11) Depth: 86/24 00:04:58 2524mN

[Modern Times]

What hash size were you using Uri ?

[Jouni]

Reckless 0.10.0-dev-6abcff05 has here some kind of search explosion. Nothing happens after 2 seconds .

[Uri Blass]

What hash size were you using Uri ?

4096 mbytes hash but it was 6 cores so I am not sure you can reproduce it.