Author: Brian Katz
Date: 14:38:20 12/29/03
I set up this 9 piece ending to see if the Fritz 8 engine would see through to a 5 piece Tablebase ending and that it does! Check it out. Coral the Knight and win it, is the theme. Position is below. Check out this ending with various Tablebase Depth settings. It does make a difference, as evidenced below. Have fun and check it out. Brian [D]4B2n/8/7k/B4K2/1B6/8/3q4/4q2n w This is a position where if we took away the two Queens and White’s extra Black squared Bishop, one viable idea would be to play 1.Be1… to coral the Black h1 Knight and then attack it with the White squared Bishop, to get into a forced winning 5 piece Tablebase ending with K+B+B vs K+N. That 5 piece ending can be in some positions at least 73 moves to mate, perhaps more. This is a 9 piece position, yet Fritz 8 with the Tablebases can see through that to the forced winning 5 piece ending. I was under the impression that with the Nalimov Tablebases, an engine could see through to a 5 piece ending, a few moves before it reaches it. I didn’t realize that it would see through to it with 9 pieces on the board. However, that still is only a few moves before reaching the ending. Just how many moves before the ending is reached, will the Tablebases be accessed? Notice that with the Default Tablebase Depth of 3, it takes 00:41:12 to see through to a mate in 43 moves. If you now change the Tablebase Depth to 0 (Zero) it only takes 00:03:11 to find a forced mate, which in this case is 78. It finds the forced mates and then ends the search with that. Without the Tablebases Fritz 8 may never find the mate but it will win the h1 Knight. I have that evaluation down below as well. I stopped it after 10 minutes as it was stuck at Analysis by Fritz 8: With Tablebase Depth set at the Default setting of 3 1.Bxd2+! +- (1.78) Depth: 7/17 00:00:00 12kN 1.Bxd2+! +- (2.16) Depth: 7/17 00:00:00 12kN 1.Bxd2+! +- (2.72) Depth: 7/17 00:00:00 14kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 7/19 00:00:00 25kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 8/18 00:00:00 32kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 9/18 00:00:00 48kN, tb=2 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kd4 Kf6 7.Bh4+ Kf5 8.Bxh1 +- (3.94) Depth: 10/21 00:00:00 83kN, tb=18 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kd4 Kf6 7.Bh4+ Kf5 8.Bxh1 +- (3.94) Depth: 11/22 00:00:00 158kN, tb=44 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kf4 Kg6 7.Bxh1 Ng5 8.Bc3 +- (4.03) Depth: 12/24 00:00:00 337kN, tb=131 1.Bxd2+! +- (4.31) Depth: 13/27 00:00:00 709kN, tb=333 1.Bxd2+! +- (4.59) Depth: 14/31 00:00:01 2009kN, tb=957 1.Bxd2+-- +- (4.31) Depth: 15/25 00:00:02 2866kN, tb=1736 1.Bxd2+ Qxd2 2.Bxd2+ +- (4.31) Depth: 15/27 00:00:03 3224kN, tb=2270 1.Bxd2+! +- (4.59) Depth: 16/33 00:00:06 6343kN, tb=4619 1.Bxd2+! +- (4.88) Depth: 16/34 00:00:11 12608kN, tb=6945 1.Bxd2+! +- (5.44) Depth: 16/34 00:00:14 15234kN, tb=8966 1.Bxd2+ Kg7 2.Bh6+ Kg8 3.Bxe1 Nf7 4.Ke6 Nh8 5.Kf6 Ng3 6.Bxg3 Kh7 7.Bd2 Kg8 +- (8.47) Depth: 16/35 00:01:07 72411kN, tb=40764 1.Bxd2+! +- (8.75) Depth: 17/39 00:01:10 75420kN, tb=45585 1.Bxd2+! +- (9.03) Depth: 17/39 00:01:10 76049kN, tb=49233 1.Bxd2+! +- (9.59) Depth: 17/41 00:01:11 76732kN, tb=52859 1.Bxd2+ Kg7 2.Bh6+ Kg8 3.Bxe1 Nf7 4.Ke6 Nh8 5.Kf6 Kh7 6.Bc6 Kg8 7.Bxh1 +- (10.63) Depth: 17/41 00:01:20 87755kN, tb=70394 1.Bxd2+ Kh7 2.Bxe1 Kg8 3.Bac3 Kf8 4.Bc6 +- (10.63) Depth: 18/34 00:01:37 105391kN, tb=92531 1.Bxd2+! +- (10.91) Depth: 19/35 00:01:46 115933kN, tb=113743 1.Bxd2+! +- (11.19) Depth: 19/38 00:02:11 147066kN, tb=150091 1.Bxd2+! +- (11.47) Depth: 20/33 00:02:23 161798kN, tb=187965 1.Bxd2+! +- (11.75) Depth: 20/36 00:02:30 169893kN, tb=217663 1.Bxd2+ Kh7 2.Bxe1 Kg8 3.Bac3 Kf8 4.Bc6 +- (11.81) Depth: 20/40 00:02:50 194860kN, tb=258561 1.Bxd2+! +- (12.09) Depth: 21/40 00:03:46 262657kN, tb=361219 1.Bxd2+! +- (12.38) Depth: 21/40 00:04:07 289712kN, tb=419264 1.Bxd2+! +- (12.94) Depth: 21/40 00:04:09 292458kN, tb=455192 1.Bxd2+! +- (13.22) Depth: 22/39 00:18:32 1507762kN, tb=1945255 1.Bxd2+! +- (13.50) Depth: 22/39 00:19:06 1556641kN, tb=2065116 1.Bxd2+! +- (14.06) Depth: 22/39 00:19:33 1595740kN, tb=2191457 1.Bxd2+ Kg7 2.Bh6+ Kh7 3.Bxe1 Ng3+ 4.Bxg3 +- (#43) Depth: 22/44 00:41:12 3390580kN, tb=5015697 1.Bxd2+ Kg7 2.Bh6+ Kh7 3.Bxe1 Ng3+ 4.Bxg3 +- (#43) Depth: 22/44 00:41:26 3405420kN, tb=5031493 (Katz, Eatontown 29.12.2003) Analysis by Fritz 8: With Tablebase Depth set at 0 (Zero) 1.Bxd2+ Kg7 2.Bxe1 Nf7 3.Bac3+ Kf8 +- (7.22) Depth: 7/7 00:00:00 1.Bxd2+ Kg7 2.Bxe1 Nf7 3.Bac3+ Kf8 +- (7.22) Depth: 8/8 00:00:00 1.Bxd2+ Kg7 2.Bxe1 Nf7 3.Bac3+ Kf8 +- (7.22) Depth: 9/9 00:00:00 1kN 1.Bxd2+-- +- (6.72) Depth: 10/20 00:00:00 98kN, tb=483 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 +- (5.84) Depth: 10/26 00:00:00 176kN, tb=1018 1.Bxd2+-- +- (5.56) Depth: 11/20 00:00:00 219kN, tb=1260 1.Bxd2+ Qxd2 2.Bxd2+ +- (5.56) Depth: 11/27 00:00:00 252kN, tb=1709 1.Bxd2+-- +- (5.28) Depth: 12/20 00:00:00 340kN, tb=2204 1.Bxd2+ Qxd2 2.Bxd2+ +- (5.28) Depth: 12/27 00:00:00 411kN, tb=2907 1.Bxd2+! +- (5.56) Depth: 13/27 00:00:00 637kN, tb=4850 1.Bxd2+! +- (5.84) Depth: 13/27 00:00:00 678kN, tb=5881 1.Bxd2+! +- (6.41) Depth: 13/27 00:00:00 750kN, tb=7266 1.Bxd2+ Qe3 2.Bxe3+ Kh7 3.Bc6 Ng3+ 4.Kf4 Nf1 5.Be4+ Kg8 6.Bc3 Nf7 7.Bg2 Nh2 8.Kg3 Nd6 9.Kxh2 Nf5 10.Bd5+ Kf8 +- (7.53) Depth: 13/32 00:00:04 3160kN, tb=24768 1.Bxd2+ Kg7 2.Bxe1 Nf7 3.Bc6 Nd6+ 4.Ke6 Nc4 5.Bxh1 Kg8 6.Bed2 Nb2 7.Bd5 Nd1 8.Bac3 +- (7.78) Depth: 14/29 00:00:07 5859kN, tb=50686 1.Bxd2+ Kg7 2.Bh6+ Kg8 3.Bxe1 Nf7 4.Kf6 Nd6 5.Bc6 Kh7 6.Bf4 Nc8 7.Bxh1 Nb6 8.Be4+ Kg8 9.Bc3 Nd7+ 10.Kf5 Kf7 +- (7.88) Depth: 15/31 00:00:13 10243kN, tb=98998 1.Bxd2+! +- (8.16) Depth: 16/31 00:00:19 15091kN, tb=160407 1.Bxd2+! +- (8.44) Depth: 16/37 00:00:28 22762kN, tb=251242 1.Bxd2+! +- (9.00) Depth: 16/37 00:00:29 24131kN, tb=284268 1.Bxd2+! +- (9.28) Depth: 17/36 00:00:39 29933kN, tb=368142 1.Bxd2+! +- (9.56) Depth: 17/36 00:00:39 30756kN, tb=412417 1.Bxd2+! +- (10.13) Depth: 17/36 00:00:41 32085kN, tb=470061 1.Bxd2+ Kg7 2.Bh6+ Kg8 3.Bxe1 Nf7 4.Ba4 Nh8 5.Bb3+ Kh7 6.Kf6 +- (10.34) Depth: 17/36 00:00:51 38593kN, tb=563567 1.Bxd2+! +- (10.63) Depth: 18/41 00:00:57 43736kN, tb=655531 1.Bxd2+! +- (10.91) Depth: 18/41 00:01:01 48422kN, tb=752255 1.Bxd2+! +- (11.47) Depth: 18/41 00:01:39 86258kN, tb=1126982 1.Bxd2+ Qe3 2.Bxe3+ Kh7 3.Be1 Kg8 4.Bd4 Kf8 5.Bc6 Nf2 6.Bexf2 Nf7 7.Bg7+ +- (16.19) Depth: 18/41 00:02:16 118067kN, tb=1543665 1.Bxd2+-- +- (15.91) Depth: 19/32 00:02:32 132726kN, tb=1649795 1.Bxd2+ Qe3 2.Bxe3+ +- (15.91) Depth: 19/34 00:02:40 141986kN, tb=1801448 1.Bxd2+! +- (16.19) Depth: 20/35 00:03:11 171403kN, tb=2172204 1.Bxd2+! +- (#78) Depth: 20/35 00:03:14 175582kN, tb=2346614 Analysis by Fritz 8: After 12 minutes With No Tablebases at all. 1.Bxd2+! +- (1.78) Depth: 7/17 00:00:00 12kN 1.Bxd2+! +- (2.16) Depth: 7/17 00:00:00 12kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 7/19 00:00:00 25kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 7/19 00:00:00 25kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 8/18 00:00:00 32kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 +- (3.94) Depth: 9/18 00:00:00 48kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kd4 Kf6 7.Bh4+ Kf5 8.Bxh1 +- (3.94) Depth: 10/21 00:00:00 84kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kd4 Kf6 7.Bh4+ Kf5 8.Bxh1 +- (3.94) Depth: 11/22 00:00:00 155kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kf4 Kg6 7.Bxh1 Ng5 8.Bc3 +- (4.03) Depth: 12/24 00:00:00 333kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kf4 Nd6 7.Bc3+ Kf7 8.Bxh1 Ke6 9.Bf3 +- (4.06) Depth: 13/26 00:00:00 706kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke6 Nc4 6.Bc3+ Kg6 7.Bxh1 Kg5 8.Be4 Kf4 9.Bd5 +- (4.06) Depth: 14/28 00:00:01 1396kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kf4 Kf6 7.Bc3+ Ke6 8.Bxh1 Nd6 9.Bf3 Nc4 10.Bd4 +- (4.03) Depth: 15/30 00:00:03 3519kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kd4 Kf6 7.Bxh1 Ng5 8.Bc3 Kf5 9.Bd5 Ne6+ 10.Kc4 Nf4 +- (4.19) Depth: 16/33 00:00:06 6870kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd6+ 5.Ke5 Nf7+ 6.Kd4 Kf6 7.Bxh1 Nd6 8.Bh4+ Kg7 9.Kc5 Nf5 10.Bg5 Kg6 +- (4.25) Depth: 17/34 00:00:11 12586kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nh6+ 5.Ke6 Kg6 6.Bxh1 Ng4 7.Be4+ Kh5 8.Bc3 Kg5 9.Bd5 Nf2 +- (4.28) Depth: 18/35 00:00:25 27348kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd8 5.Bxh1 Kf7 6.Be4 Ke7 7.Ke5 Nf7+ 8.Kd5 Kd7 9.Kc5 Ng5 10.Bc6+ Kc8 +- (4.28) Depth: 19/36 00:00:43 47336kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd8 5.Bxh1 Kf7 6.Ke5 Ke8 7.Kd5 Nf7 8.Bc3 +- (4.34) Depth: 20/39 00:01:22 90318kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd8 5.Bxh1 Kf7 6.Ke5 Ke8 7.Kd5 Kd7 8.Be4 Nf7 9.Bg3 +- (4.38) Depth: 21/39 00:02:46 184322kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd8 5.Bxh1 Kf7 6.Ke5 Ke8 7.Kd5 Kd7 8.Be4 Kc8 9.Bh4 Nf7 10.Bg6 +- (4.38) Depth: 22/43 00:05:39 378729kN 1.Bxd2+ Qxd2 2.Bxd2+ Kg7 3.Be1 Nf7 4.Bc6 Nd8 5.Bxh1 Kf7 6.Ke5 Ke8 7.Kd5 Nf7 8.Bg3 Ke7 9.Be4 Nh6 10.Bd6+ Kf6 +- (4.41) Depth: 23/44 00:11:56 802427kN (Katz, Eatontown 29.12.2003)
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