An Original Troitzky Mate

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Pressie

An Original Troitzky Mate

Post by Pressie »

For those who enjoy the challenge, I doubt that any engine on normal play settings will find the brilliant RC8(!!) in any reasonable time.

[d] rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w


After the forced 1... Kxc8 2. Ba6 Kb8 3. b7 ... how long does it take your engine to see that black is lost?

[d] rk1b4/pP1p2p1/B7/5P2/8/2K5/8/8 b

Troitzky brilliance was in seeing the threat of the lone bishop mate by marching his king to d7.

The original game went :

1.Rc8 Kxc8 2. Ba6+ Kb8 3. b7 Bb6 4. Kc4 Bc7 5. Kd5 Bg3 6. f6! Gxf6 7. Ke4 Bh2 8. Kf5 Be5 9. Kg6 d5 10. Kf5 d4 11. Ke6 d3 12. Kd7 d2 13. bxa8Q+ Kxa8 14. Kc8 d1Q 15. Bb7 Mate

It is true that Black king can avoid the Troitzky mate and extend the game by fleeing the b8 square, but the loss is inevitable.
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tjfroh
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Re: An Original Troitzky Mate

Post by tjfroh »

Yes. Deep Rybka 3 didn't find it in less than ten minutes. Rybka prunes out the Rc8 sacrifice.

1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bf6+ 4. Kc4 Bh4 5. Kc5 Bg3 6. Kd4 Bd6 7. Kd5 Be7 8. Ke4 Bc5 9. Kf4 Bd4 10. Kg5 g6 11. Kxg6 Bc5 12. f6 Bb6 13. Kf7 Bc5 14. Ke8 Bf8 15. Kxd7 Bc5 16. bxa8=Q+ Kxa8 17. Kc8 Be7 18. Bb7# *

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Dirt
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Re: An Original Troitzky Mate

Post by Dirt »

Toga 1.4 beta5c finds Rc8+ quickly, just over a minute on my slow system, but the score still shows white behind. Nothing really changed, other than depth, during the eight minutes I left it running.
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bob
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Re: An Original Troitzky Mate

Post by bob »

Pressie wrote:For those who enjoy the challenge, I doubt that any engine on normal play settings will find the brilliant RC8(!!) in any reasonable time.

[d] rk1b4/p2p2p1/1P6/2R2P2/8/2K5/8/5B2 w


After the forced 1... Kxc8 2. Ba6 Kb8 3. b7 ... how long does it take your engine to see that black is lost?

[d] rk1b4/pP1p2p1/B7/5P2/8/2K5/8/8 b

Troitzky brilliance was in seeing the threat of the lone bishop mate by marching his king to d7.

The original game went :

1.Rc8 Kxc8 2. Ba6+ Kb8 3. b7 Bb6 4. Kc4 Bc7 5. Kd5 Bg3 6. f6! Gxf6 7. Ke4 Bh2 8. Kf5 Be5 9. Kg6 d5 10. Kf5 d4 11. Ke6 d3 12. Kd7 d2 13. bxa8Q+ Kxa8 14. Kc8 d1Q 15. Bb7 Mate

It is true that Black king can avoid the Troitzky mate and extend the game by fleeing the b8 square, but the loss is inevitable.
Crafty finds this instantly:

Code: Select all

               13     0.52  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. bxa8=Q+ Kxa8 5. Kc4 d6 6. Kd5 Bg3
                                    7. Ke4 Bf2 8. Kd5 Bc5 9. Bd3
               13->   0.52  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. bxa8=Q+ Kxa8 5. Kc4 d6 6. Kd5 Bg3
                                    7. Ke4 Bf2 8. Kd5 Bc5 9. Bd3 (s=5)
               14     0.59  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd5 <HT> (s=4)
               14->   0.88  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd5 <HT> (s=4)
               15     0.96  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 d6 7.
                                    Kd5 Bh2 8. bxa8=Q+ Kxa8 9. Kc6 Kb8
                                    10. Kd5 Be5 <HT> (s=3)
               15->   1.61  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 d6 7.
                                    Kd5 Bh2 8. bxa8=Q+ Kxa8 9. Kc6 Kb8
                                    10. Kd5 Be5 <HT> (s=10)
               16     1.73  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 d6 7.
                                    Kd5 <HT> (s=9)
               16->   3.09  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 d6 7.
                                    Kd5 <HT> (s=10)
               17     3.28  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bg3 9. Kd5 Bh2 10. Kc5
                                    Bf4 11. Kd4 <HT> (s=9)
               17->   6.20  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bg3 9. Kd5 Bh2 10. Kc5
                                    Bf4 11. Kd4 <HT> (s=10)
               18     6.65  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bg3 9. Kd5 d6 10. Kc6
                                    g5 11. bxa8=Q+ Kxa8 12. f6 (s=9)
               18->  13.09  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bg3 9. Kd5 d6 10. Kc6
                                    g5 11. bxa8=Q+ Kxa8 12. f6 (s=11)
               19    13.75  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bg3 9. Kd5 d6 10. bxa8=Q+
                                    Kxa8 11. Kc6 Kb8 <HT> (s=10)
               19->  27.26  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bg3 9. Kd5 d6 10. bxa8=Q+
                                    Kxa8 11. Kc6 Kb8 <HT> (s=12)
               20    29.47  -0.38   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bf4 9. Kd4 Bd6 10. Ke4
                                    Bb4 11. Kd5 Ba3 12. Ke5 <HT> (s=11)
               20->  59.67  -0.38   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bf4 9. Kd4 Bd6 10. Ke4
                                    Bb4 11. Kd5 Ba3 12. Ke5 <HT> (s=8)
               21     1:01  -0.39   1. Rc8+ Kxc8 2. Ba6+ Kb8 3. b7 Bh4
                                    4. Kd4 Be1 5. Kd5 Bg3 6. Ke4 Bd6 7.
                                    Kd4 Bh2 8. Kc5 Bf4 9. Kd4 Bd6 10. Ke4
                                    Bg3 11. Kd4 d6 12. Kd5 Be5 13. bxa8=Q+
                                    Kxa8 (s=7)
I did not try to step through the game to see where/if it discovers a forced win...
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Pressie

Re: An Original Troitzky Mate

Post by Pressie »

It is interesting to see that Crafty and Toga both find Rc8. Rybka does not find the move in the hour that I ran it.

From the second position:


[d] rk1b4/pP1p2p1/B7/5P2/8/2K5/8/8 b

It took Rybka 3 on my Quad over 17 minutes to see the loss, the score changes to -5.00+

I think that this is another one of those positions that good human players can see better than current engines.
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