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Subject: an idea for better personality for fruit2.2

Author: Uri Blass

Date: 23:56:07 10/01/05


The idea is to reduce the history threshold of fruit.

I looked at one of the games of fruit2.2 in WBEC and I found that fruit
blundered because of history based pruning against Sjeng(you can download the
game at the WBEC page in games 1-252 of the premier division)

http://wbec-ridderkerk.nl/

The relevant position when fruit started to blunder was at move 44:

I tested 3 options for fruit2.2 with clean 512 mbytes hash(I give only part of
the analysis otherwise the post may be too long)

first fruit default personality needs a very long time to find Rxd1 at depth 18

251: DeepSjeng X2-x64 - Fruit WCCC'05, WBEC11 Premier Division 2005
[D]7q/5pk1/2QP1np1/p7/4p3/4N1P1/P3KP2/3R3r b - - 0 1

Analysis by Fruit 2.2:

44...Rh2 45.Qb5 Qh3 46.Qe5 Qc8 47.Qxa5 Qe6 48.Rd2 Qh3 49.Qe5 Qc8 50.a4 Qc1
  =  (0.02)   Depth: 13/38   00:00:13  10214kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 13/38   00:00:14  11604kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 14/38   00:00:17  14112kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 15/44   00:00:26  22060kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 16/44   00:00:40  34667kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 17/46   00:01:09  61015kN
44...Qh5+ 45.g4 Nxg4 46.Rxh1 Nh2+ 47.Ng4 Qxg4+ 48.Kd2 Qf4+ 49.Kd1 Qf3+ 50.Kc2
Qxf2+ 51.Kb1 Nf3 52.Qc3+ Qd4 53.Qxd4+ Nxd4 54.d7 Ne6 55.Rd1 Nd8 56.Kc2 f5 57.Rd5
a4 58.Rb5
  ²  (0.43)   Depth: 18/55   00:04:22  233637kN
44...Rh2 45.Qc3 Qh5+ 46.Kd2 Qb5 47.Kc1 Rh5 48.a4 Qd7 49.Ng4 Qxg4 50.d7 Rh8
51.d8Q Rxd8 52.Rxd8 Qf5 53.Qd4 Qg5+ 54.Kb2 Qf5 55.Qe3 Qe5+ 56.Ka2
  ²  (0.42)   Depth: 18/58   00:15:55  798943kN
44...Rxd1 45.Kxd1 Qh5+ 46.Ke1 Qh1+ 47.Ke2 Qb1 48.a4 Qd3+ 49.Ke1 Qb1+ 50.Ke2
  =  (0.00)   Depth: 18/58   00:17:35  893189kN

(,  02.10.2005)

second fruit with history threshold=50 can do it more than twice faster



251: DeepSjeng X2-x64 - Fruit WCCC'05, WBEC11 Premier Division 2005
7q/5pk1/2QP1np1/p7/4p3/4N1P1/P3KP2/3R3r b - - 0 1

Analysis by Fruit 2.2:

44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Kf1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+ 50.Ke2
  =  (0.00)   Depth: 13/44   00:00:19  14704kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Kf1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+ 50.Ke2
  =  (0.00)   Depth: 14/44   00:00:22  17379kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Kf1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+ 50.Ke2
  =  (0.00)   Depth: 15/44   00:00:30  25494kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Kf1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+ 50.Ke2
  =  (0.00)   Depth: 16/44   00:01:00  52693kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Nf1 Qf3 49.g5 Ng4 50.Qc2 Qf5
51.Ng3 Qxg5 52.Qc3+ Qf6 53.Nxe4 Qxc3+ 54.Nxc3 Ne5 55.Ne4 f6
  ²  (0.61)   Depth: 17/57   00:02:02  106753kN
44...Rh2 45.Qc3 Qh5+ 46.Kd2 Qb5 47.Kc1 Rh5 48.a4 Qd7 49.Ng4 Qxg4 50.d7 Rh8
51.d8Q Rxd8 52.Rxd8 Qe2 53.Qc5 Kh7 54.Kb1
  ²  (0.34)   Depth: 17/61   00:06:41  335340kN
44...Rxd1 45.Kxd1 Qh1+ 46.Ke2 Qb1 47.a4 Qd3+ 48.Ke1 Qb1+ 49.Ke2
  =  (0.00)   Depth: 17/61   00:07:32  382380kN

Third fruit with no history pruning needs even less time(inspite of it I suggest
testers to start by testing history pruning=50 and to continue testing reducing
history pruning only if it performs better)


251: DeepSjeng X2-x64 - Fruit WCCC'05, WBEC11 Premier Division 2005
7q/5pk1/2QP1np1/p7/4p3/4N1P1/P3KP2/3R3r b - - 0 1

Analysis by Fruit 2.2:

44...Rh2 45.Qb5 Qh3 46.Qe5 Qc8 47.Qxa5 Qe6 48.Rd4 Nd7 49.g4 Qf6 50.Rxe4 Qxd6
  =  (0.01)   Depth: 13/47   00:00:43  33997kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 13/47   00:00:47  37549kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Ke2 Qf3+ 49.Ke1 Qh1+
  =  (0.00)   Depth: 14/47   00:00:54  43952kN
44...Qh5+ 45.g4 Qh3 46.Rxh1 Qf3+ 47.Ke1 Qxh1+ 48.Nf1 Qf3 49.g5 Ng4 50.Qc2 Qf5
51.Ne3 Qxg5 52.Qxe4 Ne5 53.Qd4
  ²  (0.32)   Depth: 15/47   00:01:37  81576kN
44...Rh2 45.Qc3 Qh5+ 46.Kd2 Qb5 47.Kc1 Rh5 48.a4 Qb6 49.d7 Rc5 50.Nc4 Qd8 51.Rd6
Rf5 52.Qe3 Kf8 53.Qh6+ Kg8
  ²  (0.31)   Depth: 15/49   00:04:09  204284kN
44...Rxd1 45.Kxd1 Qh1+ 46.Ke2 Qb1 47.a4 Qd3+ 48.Ke1 Kg8 49.Qc8+ Kg7 50.Qc6
  =  (0.00)   Depth: 15/49   00:04:28  222394kN
44...Rxd1 45.Kxd1 Qh1+ 46.Ke2 Qb1 47.a4 Qd3+ 48.Ke1 Kg8 49.Qc8+ Kg7 50.Qc6
  =  (0.00)   Depth: 16/49   00:05:31  281103kN
44...Rxd1 45.Kxd1 Qh1+ 46.Ke2 Qb1 47.a4 Qd3+ 48.Ke1 Kg8 49.Qc8+ Kg7 50.Qc6
  =  (0.00)   Depth: 17/50   00:07:01  365176kN

(,  02.10.2005)

Note that you may need the game to reproduce the exact analysis

Note also that fruit blundered again in this game after Qh5+ g4 and played Nxg4
and I found that fruit with clear hash does not do that blunder and I guess that
having knowledge in hash prevents some history based pruning and help Qh3 to
fail low faster so Ng4 becomes better at depth 16.

Uri



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