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Subject: Re: confronting Bob with an old posting from him

Author: Vincent Diepeveen

Date: 15:45:15 06/29/98

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On June 28, 1998 at 20:24:15, jonathan Baxter wrote:

>On June 28, 1998 at 20:06:52, Vincent Diepeveen wrote:
>
>>So when i said: 18-20 ply is easy to do, then people laughed at me.
>>
>>Right now, diep gets after a day of search already 18-20.
>>It needs around 10k * 3600 * 24 = 840M nodes.
>>
>>That's with R=3 (for most programs R=2 and R=3 make no diff, but in
>>Diep it does), but nevertheless, this was considered *undoable* 2.5 years ago.
>>
>>Note that this is just with 60MB for hash, and at those slow levels
>>a doubling of hash give another ply because of the huge load factor.
>>
>>How opinions change. So 20+ ply for Diep is easily doable with 200M
>>nodes a second. In fact with say 1 gig for hashtables instead of the
>>60M i'm using now, i'll get 20 within few
>>seconds.
>
>Just to see how dumb this statement is: with enough forward pruning *any*
>program can search the full game tree and announce draw or win or whatever on
>the first move, for a stated "ply" of 200+. But unless it is always right, you
>can't claim it is searching to that depth. End of story.
>
>Jonathan Baxter.

Forward pruning works ok, i compensate with extensions a *lot*.

So if i'm getting 20 ply after 24 hours, then it really is 20 ply in normal
positions. It just prunes out some lines where you give directly a queen
away. I think that the chance that giving a queen away or something like
that wins the game is very little. No doubt that it'll look it'll search that
line at least 20-4 = 16 ply.

Still. If i turn OFF forward pruning then i get this 20 ply easily with a huge
hashtable. Yet i don't HAVE such a huge hashtable, nor a PII-300.

I have at maximum 60MB hash, which gives already a *huge* depth,
only some crap gets deleted last few plies.

So i'm talking about a program that practical *gets* 20 ply, just
a very few positions where there is a 20 ply trick at least with giving away
material and stuff, *might* get missed.

Note that my mating extensions do a rather good job.

For example win at chess 141:

4r1k1/p1qr1p2/2pb1Bp1/1p5p/3P1n1R/1B3P2/PP3PK1/2Q4R w Qc1xNf4 WinAtChess.141

00:00 113 1->1 -3.87 Rh4xf4 Bd6xf4 Qc1-c5
00:00 517 1->1 -2.42 Kg2-f1 Re8-e2
00:00 744 1->2 -2.39 Kg2-f1 Re8-e2 Bf6-e5
00:00 3266 1->3 -2.42 Kg2-f1 Re8-e2 Kf1-g1
00:01 14255 1->4 -2.48 Kg2-f1 Re8-e2 Rh1-h2 a7-a5 Kf1-g1
00:03 41872 1->4 2.98 Qc1xf4 Qc7-d8 Bf6-e5
00:04 53482 1->5 8.56 Qc1xf4 Qc7-d8 Rh4xh5 Qd8xf6 Qf4xf6 g6xh5
00:16 202646 2->6 MATE06 Qc1xf4 Bd6xf4 Rh4xh5 g6xh5 Rh1xh5 Bf4-h6 Rh5xh6 Qc7-g3
Kg2xg3 Re8-e2 Rh6-h8
00:20 239812 3->7 MATE06 Qc1xf4 Bd6xf4 Rh4xh5 g6xh5 Rh1xh5 Bf4-h6 Rh5xh6 Qc7-g3
Kg2xg3 Re8-e2 Rh6-h8
quit

Nolot #2
r4rk1/pp1n1p1p/1nqP2p1/2b1P1B1/4NQ2/1B3P2/PP2K2P/2R5 w - - bm
Rxc5!

00:00 188 1->1 -3.07 Ne4xc5 Nd7xc5
00:00 210 1->1 -3.06 h2-h4
00:00 211 1->1 -3.00 h2-h3
00:00 226 1->1 -2.85 Ne4-f6 Nd7xf6 Bg5xf6
00:00 231 1->1 -2.82 Bg5-e7
00:00 234 1->1 -2.68 Bg5-h6
00:00 1384 1->2 -3.35 Bg5-h6 Qc6-b5 Ke2-d1
00:00 1552 1->2 -2.85 Ne4-f6 Nd7xf6 Bg5xf6
00:00 1855 1->3 -2.85 Ne4-f6 Nd7xf6 Bg5xf6
00:00 3129 1->3 -1.50 Ne4xc5 Nd7xc5 Qf4-e3
00:01 6845 1->4 -2.74 Ne4xc5 Nd7xc5 Bg5-f6
00:02 23212 1->5 -3.08 Ne4xc5 Nd7xc5 Qf4-b4 Nb6-d7 Qb4-f4
00:04 48858 2->6 -3.34 Ne4xc5 Nd7xc5 Qf4-b4 Nb6-d7 Bg5-f6 Nc5-d3 Rc1xc6
00:09 116252 2->6 -2.80 Bg5-h6 Qc6-b5 Ke2-d1 Qb5-f1 Kd1-c2 Qf1-e2 Kc2-b1 Bc5-d4
Ne4-f6 Nd7xf6 Qf4xd4
00:20 244652 3->7 -2.80 Bg5-h6 Qc6-b5 Ke2-d1 Qb5-f1 Kd1-c2 Qf1-e2 Kc2-b1 Bc5-d4
Ne4-f6 Nd7xf6 Qf4xd4
00:33 399303 3->7 -2.27 a2-a4 h7-h6 Bg5xh6 Nb6xa4 Ne4xc5 Qc6-b5
00:43 515515 4->8 -3.99 a2-a4 Nb6xa4 Ne4-f6 Nd7xf6 Bb3xa4 b7-b5 Qf4-c4 b5xa4 Qc4
xc5
02:16 1655957 4->8 -2.76 Bg5-h6 Qc6-b5 Ke2-d2 Bc5-b4 Kd2-e3 Qb5xe5 Qf4xe5 Nd7xe5
 a2-a3 Bb4-a5 Ne4-f6
04:01 2836391 5->9 -3.37 Bg5-h6 Qc6-b5 Ke2-d2 Bc5-d4 Ne4-f6 Nd7xf6 Qf4xd4 Rf8-e8
 e5-e6 Nb6-d5
06:42 4216433 5->9 -1.15 Rc1xc5 Nd7xc5 Ne4-f6 Kg8-h8 Qf4-h4 Qc6-b5 Ke2-f2 Nc5-d3
 Kf2-g2 Nd3-e1 Qh4xe1 Nb6-d7 Qe1-h4 h7-h5 Nf6xd7 Qb5xd7
08:37 5197732 6->10 0.00 Rc1xc5 Nd7xc5 Ne4-f6 Kg8-h8 Qf4-h4 Qc6-b5 Ke2-e3 Qb5-d3
 Ke3-f2 h7-h5 Nf6xh5 Nc5-e4 f3xe4 Qd3-d4 Kf2-f1 Qd4-d3 Kf1-f2
13:14 7548617 7->11 0.10 Rc1xc5 Nd7xc5 Ne4-f6 Kg8-h8 Qf4-h4 Qc6-b5 Ke2-e3 Qb5-d3
 Ke3-f2 h7-h5 Nf6xh5 Nc5-e4 f3xe4 Qd3-d4 Kf2-g2 Qd4xb2 Kg2-h3 Qb2-c3 Nh5-g3 Kh8-
g8 Bg5-f6 Qc3-c8 Kh3-g2
33:30 18176564 8->12 2.65 Rc1xc5 Qc6xe4 f3xe4 Nd7xc5 Bg5-h6 Nc5xb3 a2xb3 Nb6-d7
Bh6xf8 Ra8xf8 Ke2-e3
59:01 31434222 9->13 2.47 Rc1xc5 Qc6xe4 f3xe4 Nd7xc5 Bg5-h6 Nc5xb3 a2xb3 Nb6-d7
Bh6xf8 Ra8xf8 Qf4-g5 Kg8-g7 e5-e6 f7xe6 Qg5-e7

Nolot #10
r1b2rk1/1p1nbppp/pq1p4/3B4/P2NP3/2N1p3/1PP3PP/R2Q1R1K w - - bm Rxf7

00:00 7 1->1 -4.06 Bd5xf7 Rf8xf7 Rf1xf7
00:00 11 1->1 -4.05 Bd5xb7 Bc8xb7
00:00 35 1->1 -3.94 Rf1xf7 Rf8xf7
00:00 52 1->1 0.06 Nd4-f5
00:00 176 1->2 -0.32 Nd4-f5 Be7-f6
00:00 575 1->3 -0.34 Nd4-f5 Be7-f6 Ra1-b1
00:00 1807 1->4 -0.60 Nd4-f5 Be7-f6 Ra1-b1 Nd7-e5
00:01 10307 1->5 -0.72 Nd4-f5 Be7-f6 Ra1-a2 Kg8-h8
00:02 24729 1->5 -0.57 Qd1-d3 Be7-f6 Nc3-e2 Nd7-c5 Qd3xe3 Qb6xb2
00:03 32869 2->6 -0.58 Qd1-d3 Be7-f6 Nc3-e2 Bf6-g5 Nd4-b3
00:07 83015 2->6 -0.33 Bd5-b3 Be7-f6 Nc3-d5 Qb6-c5 c2-c3 Bf6-g5
00:10 119222 3->7 -0.17 Bd5-b3 Qb6-c5 Nc3-d5 Be7-g5 a4-a5
00:27 342429 4->8 -0.13 Bd5-b3 Be7-f6 Nc3-d5 Qb6-c5 c2-c3 Bf6-g5 a4-a5
01:08 855177 5->9 0.04 Bd5-b3 Be7-g5 Nc3-d5 Qb6-a5 Qd1-h5 Qa5-d8 Nd4-f5 g7-g6 Nf
5xd6
02:40 2043189 6->10 0.12 Bd5-b3 Be7-f6 Nc3-d5 Qb6-a7 c2-c3 Bf6-g5 Qd1-h5 h7-h6 a
4-a5
08:18 5325215 7->11 -0.01 Bd5-b3 Be7-g5 Nc3-d5 Qb6-d8 Nd4-f5 Nd7-c5 Nf5xe3 Bg5xe
3 Nd5xe3 Bc8-e6 Bb3xe6
22:41 13898604 7->11 0.23 Rf1xf7 Rf8xf7 Bd5xf7 Kg8xf7 Qd1-h5 Kf7-g8 Qh5-e8 Be7-f
8 Nc3-d5 Qb6xd4 Nd5-e7 Kg8-h8 Ra1-f1 Qd4-f6 Rf1xf6 g7xf6 Ne7xc8

Try that at other programs. Diep sees Rxf7 at 11 ply which is so called
selective and I did NOT make any adjustments to find Rxf7.

Some versions even found it earlier than this 11 ply, and
i bet that Deep Blue doesn't get it at 11 ply, although it needs
special processors and SP hardware in order to get 11 ply.

Vincent




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