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Subject: Re: Not so fast

Author: Vincent Diepeveen

Date: 15:24:35 09/16/01

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On September 16, 2001 at 17:38:05, Uri Blass wrote:

>On September 16, 2001 at 16:30:27, Bruce Moreland wrote:
>
>>On September 16, 2001 at 16:15:32, Vincent Diepeveen wrote:
>>
>>>On September 16, 2001 at 00:36:22, Bruce Moreland wrote:
>>>
>>>>Vincent emailed me and asked me to run these.  I ran them on a quad 450 Xeon.
>>>>
>>>>[D]8/p4bpk/7p/3rq3/3Npp2/PPQ3P1/3R1PKP/8 w - - 0 1
>>>>
>>>>I get gxf4 until ply 10, after which there is a switch to b4, which is a bad
>>>>move.  This fails low to -3.88 in ply 11, and gxf4 comes back with a score of
>>>>-2.48.
>>>>
>>>>Later in ply 11, f3 pops up with a score of -2.33.
>>>>
>>>>Up to here takes 89 seconds.
>>>>
>>>>f3 sticks until ply 14, at which point if fails low to -4.24, and gxf4 comes
>>>>back with a score of -3.21, resolving after about 1/2 hour.
>>>>
>>>>In ply 15, gxf4 fails low again, and the hour ended with no resolution.  It was
>>>><= -3.46.
>>>>
>>>>[D]8/p4bpk/7p/3rq3/3Npp2/PPQ2PP1/3R2KP/8 b - - 0 1
>>>>
>>>>In this one, I have exf3+, with a score of +2.35 in ply 10.  After 16 seconds,
>>>>in ply 10, it finds Bh5, failing high to +2.80.
>>>>
>>>>Ply 11 was uneventful, but in ply 12, Bh5 failed high to +4.24.
>>>>
>>>>The score creeps up slightly, and the last score I got in the hour was +4.99,
>>>>ply 15, after about 45 minutes.
>>>>
>>>>I'll run the first one again all night and see what happens.
>>>>
>>>>bruce
>>>
>>>thanks!
>>>
>>>It confirms already what i suspected. f3 is losing
>>>way harder than alternatives!
>>>
>>>I do not understand why ferret needs a ply more to get -4.24 for f3
>>>than when after f3 is getting played. Possible to shine any light onto
>>>this?
>>
>>I don't see that you can draw that conclusion at all, especially in light of
>>this:
>>
>>    ply  milliseconds score           line
>>no   17  27657860   -433  -1221224784 gxf4 Qxf4 Kh1 Rh5 f3 exf3 Nxf3 Rh3 Rf2
>>                                      Bd5 Rg2 g5 Qd3+ Qe4 Qxe4+ Bxe4 Nd2 Bxg2+
>>                                      Kxg2 Rd3 Ne4 Rxb3 a4 Rb4 Nc5 Rb2+ Kg3
>>                                      --
>>no   17  41753610   -499    666953819 gxf4 Qxf4 f3 Bh5 Kf1 e3 Re2 Rxd4 Rxe3
>>                                      Rd1+ Re1 Qxf3+ Qxf3 Bxf3 Rxd1 Bxd1 b4 Kg6
>>                                      Kf2 Bc2 Ke3 Kf5 b5
>>no   17  50832840   -494  -1178700567 f3 Bh5 g4 e3 Rd1 Bg6 Qc4 e2 Re1 Rxd4 Qxe2
>>                                      Qxe2+ Rxe2 Rd3 b4 Rxa3 h4 Bd3 Rd2 Rc3 Kh3
>>
>>Column 4 (node count) is broken and should be ignored.
>>
>>gxf4 failed low to -4.99 in ply 17, and f3 overtook it at -4.94.  So mine would
>>play f3 after 50,832 seconds.
>>
>>bruce
>
>I think the differece between f3 and gxf4 is a positional difference and we have
>no logfiles of dep blue from that game so it may be interesting to look at the
>following position
>
>[D]Rr6/5kp1/1qQb1p1p/1p1PpP2/1Pp1B3/2P4P/6P1/5K2 w - - 0 1
>
>Here is Deeper blue logfile
>
>---------------------------------------
>hash guess Rb7b8,Guessing Rb8
> 8(4) #[Ra6](156)[Ra6](156) 156^ T=0
>ra8a6 Qb6c6q pd5c6Q Kf7g8 be4d5 Kg8h7 ra6a7 Rb8c8 ra7b7 Ph6h5 rb7b5P Kh7h6 rb5b7
>Rc8c7 rb7b8
> 8(6) #[Ra6](128)########################## 128  T=3
>ra8a6 Qb6c6q pd5c6Q Kf7g8 be4d5 Kg8h7 ra6a7 Rb8c8 ra7b7 Ph6h5 rb7b5P Kh7h6 rb5b7
>Rc8c7 rb7b8
> 9(6) #[Ra6](128)###########<ch> 'rb8'
>[183 sec (main.c:1847)][cont]############### 128  T=10
>ra8a6 Qb6c6q pd5c6Q Kf7g8 be4d5 Kg8h7 ra6a7 Rb8c8 ra7b7 Ph6h5 rb7b5P Kh7h6 rb5b7
>Rc8c7 rb7b8
>10(6) #[Ra6](158)[Ra6](158) 158^ T=17
>ra8a6 Qb6c6q pd5c6Q Kf7g8 be4d5 Kg8h7 ra6a7 Rb8c8 ra7b7 Ph6h5 rb7b5P Kh7h6 rb5b7
>Rc8c7 rb7b8
>10(6) #[Ra6](158)########################## 158  T=34
>ra8a6 Qb6c6q pd5c6Q Kf7g8 be4d5 Kg8h7 ra6a7 Rb8c8 ra7b7 Ph6h5 rb7b5P Kh7h6 rb5b7
>Rc8c7 rb7b8
>11(6) #[Ra6](156)########################## 156  T=99
>ra8a6 Qb6c6q pd5c6Q Kf7g8 be4d5 Kg8h7 ra6a7 Rb8c8 ra7b7 Ph6h5 rb7b5P Kh7h6 rb5b7
>Rc8c7 rb7b8
>12(6) #[Ra6](162)[TIMEOUT] 162  T=192
>ra8a6 Qb6c6q pd5c6Q Rb8c8 be4d5 Kf7e7 ra6a5 Bd6c7 ra5b5P Ke7d6 bd5f3 Kd6e7 rb5c5
>Rc8a8 bf3d5 Ke7d6
>
>You can see that the evaluation of Deeper blue at depth 12(6) was 1.62 pawn for
>white.

pawn in deep blue was 128 bob said:
  162 / 128 = 1.27

I will let diep run overnight at it.

>I am interested to know the evaluation of Ferret at depth 18 in order to compare
>with deeper blue.
>
>It may be interesting to see also the evaluation of Ferret when you increase the
>value of pieces that are not pawns to 150% of their normal value(programs may
>find quickly that black gets 2 pawns for the piece after Ra6 Qe3 so in order to
>prevent finding Ra6 Qe3 for these reasons I suggest to increase the value of
>pieces that are not pawns)
>
>I ask for Ferret's evaluation at depth 18 because other programs do not use
>singular extensions.
>
>I suspect that Ferret can find Ra6 Qe3 in both cases at depth that is smaller
>than 18 and that it can also cahnges it's mind later to Qd7+
>
>Uri



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