Author: Wilhelm Hudetz
Date: 09:34:10 01/24/05
Go up one level in this thread
On January 24, 2005 at 12:20:05, John Merlino wrote:
>On January 24, 2005 at 11:21:14, Wilhelm Hudetz wrote:
>
>>On January 24, 2005 at 09:54:04, Wilhelm Hudetz wrote:
>>
>>>Hi Jason,
>>>
>>>I think your right.
>>>I read a german translation of the manual from CM4000-Turbo,
>>>and there stands, if you set minus CM will more look to find a winning
>>>way in drawing positions.
>>>I think there is a false translation!
>>>Ok, I check this, more later.
>>>Thank you
>>>
>>>Wilhelm
>>>I better should read the english manual....
>>
>>I make some tests with different positions
>>and cfd has big influence of the search.
>>So I think it can not only be a parameter for accept draw!?
>>
>>here a testposition as example:
>>
>>8/5BK1/8/2kn4/1p2b3/8/1R3P2/8 w - - 0 62
>>
>>try different values for cfd and look how long it take to find Rd2.
>>
>>In many games I have controlled I coudn´t see that CM accept a
>>draw when he is in plus (C3PO has cfd=-10).
>>So I don´t know whats realy right.
>>
>>regards
>>Wilhelm
>
>Indeed, the Contempt for Draw value affects the search VERY MUCH! Johan could
>probably give a more complete description of how this works, but, in a nutshell:
>
>A low (negative) contempt for draw means that the engine will look for and
>attempt to steer the game towards drawish lines, even at the cost of improving
>its position. It will consistently attempt to get draws by repetition and will
>very likely trade material to simplify. This can result in boring play, and is
>likely to reduce the quality of play.
>
>A high (positive) contempt for draw means that the engine will attempt to avoid
>drawish positions, even at the cost of losing half a point. You can easily see
>an example of how this can reduce the quality of play by looking at the first
>game in the CM vs. Christiansen match in which the Alekhine personality was
>used. This personality has a +3 cfd value, which means that it won't accept a
>draw unless it is down by at least 3 points!
>
>The engine made some very poor moves attempting to attack and avoiding
>simplification.
>
>[Date "2002.9.28"]
>[Round ""]
>[White "CM9000 Alekhine"]
>[Black "LarryC"]
>[TimeControl "120+120"]
>[Result "0-1"]
>
>1.e4 {00:00 (Book)} 1...c6 {00:18} 2.d4 {00:00 (Book)} 2...d5 {00:30}
>3.exd5 {00:00 {Book)} 3...cxd5 {00:44} 4.c4 {00:00 (Book)} 4...Nf6 {
>00:59} 5.Nc3 {00:00 (Book)} 5...e6 {01:15} 6.Nf3 {00:00 (Book)} 6...Be7
>{01:37} 7.cxd5 {00:00 (Book)} 7...Nxd5 {01:52} 8.Bb5+ {00:00 (Book)}
>8...Nc6 {05:37} 9.Ne5 {02:08 (Score: 0.86, Depth: 3/12}} 9...Bd7 {07:11}
>10.Bxc6 {02:52 (Score: 0.87, Depth: 3/12)} 10...Bxc6 {07:31} 11.Nxc6 {
>05:03 {Score: 0.53, Depth: 3/12)} 11...bxc6 {07:59} 12.Nxd5 {06:50
>(Score: 0.24, Depth: 4/13)} 12...cxd5 {09:13} 13.O-O {07:53 (Score:
>-0.01, Depth: 4/13)} 13...O-O {09:26} 14.Bf4 {10:05 (Score: 0.05, Depth:
>4/13)} 14...Qb6 {12:09} 15.Qd2 {10:08 (Score: 0.05, Depth: 4/13)}
>15...Bf6 {13:02} 16.Be3 {11:31 (Score: 0.09, Depth: 4/13)} 16...a5 {
>13:34} 17.Rac1 {13:52 (Score: 0.28, Depth: 4/13)} 17...Qb4 {15:09}
>18.Rfd1 {15:29 (Score: 0.39, Depth: 3/12)} 18...Rfb8 {16:38} 19.Rc3 {
>17:44 (Score: 0.51, Depth: 3/12)} 19...Qa4 {21:19} 20.Rdc1 {19:18
>(Score: 0.67, Depth: 3/12)} 20...h6 {22:59} 21.b3 {21:33 (Score: 0.62,
>Depth: 3/12)} 21...Qb4 {23:29} 22.R1c2 {22:45 (Score: 0.58, Depth: 2/11}
>} 22...Re8 {25:16} 23.h3 {25:03 (Score: 0.54, Depth: 3/12)} 23...a4 {
>26:06} 24.Rc8 {27:20 (Score: 0.34, Depth: 4/13)} 24...Qxd2 {26:41}
>25.Rxe8+ {27:35 (Score: 0.28, Depth: 6/14)} 25...Rxe8 {26:58} 26.Rxd2 {
>31:15 (Score: 0.02, Depth: 8/15)} 26...axb3 {29:21} 27.axb3 {31:15
>(Score: -0.22, Depth: 7/13)} 27...Rb8 {29:53} 28.Rb2 {32:24 (Score:
>-0.15, Depth: 8/14)} 28...Rb4 {35:32} 29.Kf1 {34:06 (Score: -0.10,
>Depth: 8/14)} 29...Kf8 {36:33} 30.Ke2 {34:43 (Score: -0.10, Depth: 8/14}
>} 30...Bxd4 {37:22} 31.Bxd4 {37:02 (Score: -0.66, Depth: 9/15)}
>31...Rxd4 {37:36} 32.b4 {38:06 (Score: -0.77, Depth: 9/14)} 32...Ke7 {
>42:59} 33.b5 {38:06 (Score: -0.99, Depth: 10/15)} 33...Rc4 {53:20} 34.b6
>{40:07 (Score: -1.09, Depth: 8/13)} 34...Rc8 {53:35} 35.h4 {43:29
>(Score: -1.47, Depth: 9/14)} 35...Kd6 {56:02} 36.Rb3 {43:30 (Score:
>-1.43, Depth: 9/14)} 36...Rb8 {57:10} 37.Rg3 {43:55 (Score: -1.39,
>Depth: 9/14)} 37...g6 {59:43} 38.h5 {43:57 (Score: -1.44, Depth: 9/14)}
>38...g5 {01:00:30} 39.Ra3 {44:41 (Score: -1.47, Depth: 9/14)} 39...Rxb6
>{01:01:23} 40.Ra7 {47:11 (Score: -1.38, Depth: 10/14)} 40...Rb2+ {
>01:02:01} 41.Kf1 {48:46 (Score: -1.35, Depth: 10/14)} 41...f5 {01:06:48}
>42.Rh7 {50:10 (Score: -1.17, Depth: 10/14)} 42...d4 {01:15:06} 43.Rxh6 {
>50:10 (Score: -1.31, Depth: 11/15)} 43...d3 {01:15:56} 44.Ke1 {50:59
>(Score: -1.43, Depth: 10/14)} 44...Ke5 {01:22:58} 45.Rh8 {52:47 (Score:
>-1.34, Depth: 10/14)} 45...Rb1+ {01:24:23} 46.Kd2 {52:47 (Score: -0.73,
>Depth: 1/2)} 46...Rf1 {01:24:38} 47.f3 {54:40 (Score: -1.60, Depth:
>11/15)} 47...Rf2+ {01:24:56} 48.Kxd3 {56:13 (Score: -2.01, Depth: 11/15}
>} 48...Rxg2 {01:25:17} 49.h6 {01:00:12 (Score: -2.13, Depth: 12/16)}
>49...Rh2 {01:26:41} 50.Ke3 {01:01:33 (Score: -2.25, Depth: 12/16)}
>50...f4+ {01:27:31} 51.Kd3 {01:01:33 (Score: -0.78, Depth: 1/2)}
>51...Rf2 {01:27:49} 52.Rg8 {01:04:25 (Score: -2.40, Depth: 12/16)}
>52...Rxf3+ {01:28:02} 53.Kc4 {01:05:44 (Score: -2.45, Depth: 11/15)}
>53...Rh3 {01:28:16} 54.Rxg5+ {01:08:19 (Score: -2.67, Depth: 11/15)}
>54...Ke4 {01:28:35} 55.Rg1 {01:11:03 (Score: -2.93, Depth: 11/15)}
>55...Rxh6 {01:28:53 -- White Resigns} 0-1
>
>Johan, as far as I know, ALWAYS uses a cfd value of 0 in tournaments with The
>King.
>
>jm
Hi John,
thank you for explaining!
In my tests I got some better results with a little negative value.
To clear this, a value of -10 for use outside of CM-GUI is a vlue of -1 in
CM-GUI.
Wilhelm
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