Glaurung and mate solving: 2 examples

[Jouni]

I think these are stunning solutions WITHOUT any tablebases. Don't be too
modest Tord!

[D]8/8/8/6k1/3K2p1/8/5R2/8 w - -

Analysis by Glaurung 2.0.1:

75.Ke3 Kh4
± (1.05) Depth: 2 00:00:00
75.Ke3 Kh4 76.Kf4
± (1.09) Depth: 3 00:00:00
75.Ke3 Kh4 76.Kf4 g3
± (1.05) Depth: 4 00:00:00
75.Ke3 Kh4 76.Kf4 g3 77.Rf1
± (1.05) Depth: 5 00:00:00
75.Ke3 g3 76.Rf1 Kg4 77.Rh1 g2
± (1.05) Depth: 6 00:00:00 5kN
75.Ke3 g3 76.Rf1 Kg4 77.Rh1 g2 78.Rg1
± (1.05) Depth: 7 00:00:00 11kN
75.Rf7 g3 76.Ke3 Kg4 77.Rh7 g2 78.Kf2
± (1.09) Depth: 7 00:00:00 14kN
75.Rf7 Kg6 76.Rf1 Kg5 77.Ke3 Kh4 78.Kf2 Kg5
± (1.13) Depth: 8 00:00:00 26kN
75.Ke3 Kh4 76.Rf7 Kh3 77.Kf2 Kh4 78.Rh7+ Kg5 79.Kg3
+- (6.29) Depth: 8 00:00:00 28kN
75.Ke3 Kh4 76.Rf7 Kg5 77.Rg7+ Kf5 78.Rg8 g3 79.Rxg3 Ke6
+- (80.36) Depth: 9 00:00:00 38kN
75.Ke3 Kh4 76.Rf7 Kg5 77.Rg7+ Kf5 78.Rg8 g3 79.Rxg3 Ke5 80.Kf3
+- (80.41) Depth: 10 00:00:00 53kN
75.Ke4 Kh4 76.Rf7 Kg3 77.Rg7 Kg2 78.Rxg4+ Kf2 79.Kf4 Ke2 80.Rg7
+- (80.56) Depth: 10 00:00:00 65kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kd7 80.Ke5 Ke7 81.Rg7+ Kd8
+- (80.56) Depth: 11 00:00:00 106kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kd7 80.Ke5 Kc7 81.Rh6 Kd7
+- (80.56) Depth: 12 00:00:00 168kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kd7 80.Ke5 Kc7 81.Rh6 Kd7 82.Kf5
+- (80.56) Depth: 13 00:00:00 306kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kd7 80.Ke5 Kc7 81.Rh6 Kd7 82.Rf6 Ke7
+- (80.56) Depth: 14 00:00:01 562kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kf7 80.Kf5 Ke7 81.Rh6 Kd7 82.Re6 Kc7 83.Ke5
+- (80.61) Depth: 15 00:00:01 1086kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kf7 80.Rd6 Ke7 81.Ke5 Kf7 82.Re6 Kg7 83.Rf6 Kh7
+- (80.66) Depth: 16 00:00:02 1833kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kf7 80.Rd6 Ke7 81.Ke5 Kf7 82.Re6 Kg7 83.Rf6 Kh8 84.Ke6
+- (80.71) Depth: 17 00:00:03 2812kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kf7 80.Rd6 Ke7 81.Ke5 Kf7 82.Rd7+ Kg6 83.Ra7 Kg5 84.Rg7+ Kh4 85.Kf5 Kh3
+- (80.71) Depth: 18 00:00:04 4271kN
75.Ke4 g3 76.Rf7 g2 77.Rg7+ Kf6 78.Rxg2 Ke6 79.Rg6+ Kf7 80.Rd6 Ke7 81.Ke5 Kf7 82.Re6 Kg7 83.Ke4 Kh8 84.Rg6 Kh7 85.Kf5
+- (80.75) Depth: 19 00:00:06 6535kN
75.Ke4 g3 76.Rg2 Kg4 77.Rg1 Kg5 78.Rxg3+ Kf6 79.Rd3 Ke6 80.Rd5 Kf7 81.Ke5 Ke7 82.Kf5 Kf7 83.Rd7+ Kf8 84.Kf6 Kg8 85.Rf7 Kh8
+- (80.80) Depth: 20 00:00:09 9442kN
75.Ke4 g3 76.Rg2 Kg4 77.Rg1 Kg5 78.Rxg3+ Kf6 79.Kd5 Ke7 80.Ke5 Kf7 81.Rc3 Ke7 82.Rc7+ Ke8 83.Ke6 Kf8 84.Rc3 Kg7 85.Rg3+ Kh7 86.Kf6 Kh8
+- (80.80) Depth: 21 00:00:11 12559kN
75.Ke4 g3 76.Rg2 Kg4 77.Rg1 Kg5 78.Rxg3+ Kf6 79.Kd5 Ke7 80.Ke5 Kf7 81.Rc3 Ke7 82.Rc7+ Kd8 83.Kd6 Ke8 84.Ke6 Kf8 85.Rf7+ Kg8 86.Kf6 Kh8 87.Re7
+- (80.80) Depth: 22 00:00:15 17113kN
75.Ke4 g3 76.Rf8 g2 77.Rg8+ Kf6 78.Rxg2 Ke6 79.Rd2 Kf6 80.Rd6+ Ke7 81.Ke5 Kf7 82.Kf5 Ke7 83.Rd5 Kf7 84.Re5 Kg7 85.Re7+ Kf8 86.Kf6 Kg8 87.Re8+ Kh7 88.Ra8 Kh6 89.Rh8#
+- (#15) Depth: 23 00:00:20 22825kN
75.Ke4 g3 76.Rf8 g2 77.Rg8+ Kf6 78.Rxg2 Ke6 79.Rd2 Kf6 80.Rd6+ Ke7 81.Ke5 Kf7 82.Kf5 Ke7 83.Rd5 Kf7 84.Re5 Kg7 85.Re7+ Kf8 86.Kf6 Kg8 87.Re8+ Kh7 88.Ra8 Kh6 89.Rh8#
+- (#15) Depth: 24 00:00:22 26280kN
75.Ke4 g3 76.Rf8 g2 77.Rg8+ Kf6 78.Rxg2 Ke6 79.Rd2 Kf6 80.Rd6+ Ke7 81.Ke5 Kf7 82.Kf5 Ke7 83.Rd5 Kf7 84.Re5 Kg7 85.Re7+ Kf8 86.Kf6 Kg8 87.Re8+ Kh7 88.Ra8 Kh6 89.Rh8#
+- (#15) Depth: 25 00:00:26 31428kN
75.Ke4 g3 76.Rg2 Kg4 77.Rg1 Kg5 78.Rxg3+ Kf6 79.Rd3 Ke6 80.Kf4 Kf6 81.Re3 Kg6 82.Re6+ Kg7 83.Kg5 Kf7 84.Re3 Kg7 85.Rf3 Kh7 86.Kf6 Kh8 87.Kf7 Kh7 88.Rh3#
+- (#14) Depth: 26 00:00:31 38336kN
75.Ke4 g3 76.Rg2 Kg4 77.Rg1 Kg5 78.Rxg3+ Kf6 79.Rd3 Ke6 80.Kf4 Kf6 81.Re3 Kg6 82.Re6+ Kg7 83.Kg5 Kf7 84.Re3 Kg7 85.Rf3 Kh7 86.Kf6 Kh8 87.Kf7 Kh7 88.Rh3#

[D]8/8/8/8/8/2k2P2/4K3/8 w - -

Analysis by Glaurung 2.0.1:

1.f4 Kb2
+- (74.79) Depth: 2 00:00:00
1.f4 Kb4 2.Kf2
+- (74.79) Depth: 3 00:00:00
1.f4 Kb4 2.Kf2 Ka3
+- (74.79) Depth: 4 00:00:00
1.f4 Kb4 2.Kf2 Kc5 3.Kf3
+- (74.79) Depth: 5 00:00:00
1.f4 Kb4 2.Kf2 Kc5 3.Kf3 Kb4
+- (74.79) Depth: 6 00:00:00 1kN
1.f4 Kb4 2.Kf2 Kc5 3.Kf3 Kd5 4.Kg4
+- (74.79) Depth: 7 00:00:00 1kN
1.f4 Kb4 2.Kf2 Kc5 3.Kf3 Kd5 4.Kg4 Kc5
+- (74.79) Depth: 8 00:00:00 2kN
1.f4 Kb4 2.Kf2 Kc5 3.Kf3 Kd5 4.Kg4 Kd6 5.Kh4
+- (74.79) Depth: 9 00:00:00 4kN
1.f4 Kb4 2.Kf2 Kc5 3.Kf3 Kd5 4.Kg4 Kd6 5.Kh4 Ke6
+- (74.79) Depth: 10 00:00:00 5kN
1.f4 Kc4 2.Kf3 Kd5 3.Kg4 Ke6 4.Kg5 Kf7 5.Kf5 Ke7 6.Kg5
+- (74.79) Depth: 11 00:00:00 10kN
1.f4 Kc4 2.Kf3 Kd5 3.Kg4 Ke6 4.Kg5 Kf7 5.Kf5 Ke7 6.Ke5 Kd7
+- (74.79) Depth: 12 00:00:00 12kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5
+- (74.80) Depth: 12 00:00:00 14kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Ke5
+- (74.80) Depth: 13 00:00:00 17kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Ke5 Kb4
+- (74.80) Depth: 14 00:00:00 22kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Ke5 Kb4 8.f6
+- (74.80) Depth: 15 00:00:01 32kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Ke5 Kb4 8.f6 Kc5
+- (74.80) Depth: 16 00:00:01 40kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Kg6 Kd6 8.f6 Kc5 9.f7
+- (74.81) Depth: 17 00:00:01 57kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Kg6 Kd6 8.f6 Ke6 9.f7 Ke7
+- (74.81) Depth: 18 00:00:01 75kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kc5 7.Kg6 Kd6 8.f6 Ke6 9.f7 Ke7 10.Kg7
+- (74.81) Depth: 19 00:00:01 94kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg6 Kc4 8.f6 Kd5 9.f7 Ke6 10.f8Q Kd5
+- (86.56) Depth: 20 00:00:01 121kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc5 10.f8Q+ Kd5 11.Kf6 Kc4
+- (86.61) Depth: 21 00:00:01 152kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kc4
+- (86.61) Depth: 22 00:00:01 198kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Kf5
+- (86.66) Depth: 23 00:00:01 252kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qd8+ Kc5 13.Ke5
+- (86.71) Depth: 24 00:00:01 365kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qd8+ Kc5 13.Ke5 Kb4
+- (86.71) Depth: 25 00:00:01 516kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qd8+ Kc5 13.Ke5 Kc4 14.Ke4
+- (86.71) Depth: 26 00:00:01 705kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qb4+ Kd3 13.Kf5 Ke3 14.Qe4+ Kd2 15.Kf4
+- (86.81) Depth: 27 00:00:01 1104kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qb4+ Kd3 13.Kf5 Ke3 14.Qe4+ Kd2 15.Qd4+ Ke1 16.Ke4
+- (86.81) Depth: 28 00:00:02 1667kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qb4+ Kd3 13.Kf5 Ke3 14.Qc3+ Ke2 15.Ke4 Kf2 16.Kd4
+- (86.86) Depth: 29 00:00:02 2413kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg7 Kc5 8.f6 Kb4 9.f7 Kc4 10.f8Q Kc3 11.Kf6 Kd4 12.Qb4+ Kd3 13.Kf5 Ke3 14.Qc3+ Ke2 15.Ke4 Kf2 16.Qe3+ Kg2
+- (86.91) Depth: 30 00:00:04 3680kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg6 Kc5 8.f6 Kd6 9.f7 Ke7 10.Kg7 Kd6 11.f8Q+ Kd5 12.Qb4 Kc6 13.Kf6 Kc7 14.Kf5 Kd7 15.Qc5 Ke8 16.Ke6 Kd8
+- (86.96) Depth: 31 00:00:05 5212kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg6 Kc5 8.f6 Kd6 9.f7 Ke7 10.Kg7 Kd6 11.f8Q+ Kd5 12.Qb4 Kc6 13.Kf6 Kc7 14.Qc5+ Kb7 15.Qb5+ Ka8 16.Ke5 Ka7
+- (87.05) Depth: 32 00:00:07 7800kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg6 Kc5 8.f6 Kd6 9.f7 Ke7 10.Kg7 Kd6 11.f8Q+ Kd5 12.Qb4 Kc6 13.Kf6 Kc7 14.Kf5 Kd7 15.Qc5 Ke8 16.Ke6 Kd8
+- (#18) Depth: 33 00:00:10 11820kN
1.Ke3 Kc4 2.Ke4 Kc5 3.Ke5 Kc6 4.f4 Kd7 5.Kf6 Kd6 6.f5 Kd5 7.Kg6 Kc5 8.f6 Kd6 9.f7 Ke7 10.Kg7 Kd6 11.f8Q+ Kd5 12.Qb4 Kc6 13.Kf6 Kc7 14.Kf5 Kd7 15.Qc5 Ke8 16.Ke6 Kd8 17. Qc3 Ke8. 18. Qc8#

Jouni

[Tord Romstad]

I think these are stunning solutions WITHOUT any tablebases. Don't be too
modest Tord!

To a human observer, finding long mates like this a few seconds when there is no single forced line looks very impressive. For a computer program, it is actually very simple in positions where so few pieces remain on the board: The key to solving them quickly is the transposition table (often referred to by the less precise name "hash table"), a huge chunk of memory where the program stores the analysis of all the positions it has already examined in the current search. In positions where only three pieces remain, the transposition table will very quickly be filled with all possible configurations of the remaining pieces (or at least all the most relevant configurations), which enables the program to search to extremely high depths in just a fraction of a second.

When there is a forced mate, it will therefore usually be found very quickly, even when the number of moves to mate is quite big.

Tord

[Thomas Cutter]

Sometimes I play with Glaurung on the chessbase server. I remember two games, where Glaurung was particular strong in the endgame with less pieces. Since I had no TBs on the machine, Glaurung was forced to do all work for itself.

Reaching 6-men area, I checked on the Shredder-site the online TB during the game. In one game all critical moves were found (i.e. where only a single move keeps the win). However, the mate was still out of reach (more than 40 plies or so).

Although this is no prove, at least it is good evidence, that Glaurung plays endgames reasonable well.


Greetings Thomas

[playjunior]

I agree that Glaurung is a very nice engine to have when you are analyzing endgames. I especially like that it sometimes builds nice fortresses and understands there is a fortress, while other engines show some +2 or +3 score

[Mike S.]

Thx for these examples.

A useful option in Fritz is 'Scroll New Moves Only' from the context menu; right-click the engine window for it. By that, the output will keep the first line - with the decision time - and the current/last line only, as long as the first move doesn't change. It is a recommendable option to save space and to make engine output easier to read, i.e. no dozens of lines from 0...1 second.