Author: Ernst Walet
Date: 05:15:58 01/27/02
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Yes you're right, with fp on it takes Fritz another ply and twice the time to find Nf6. Ernst. Futility Pruning off New game r2r1bk1/ppqb1ppp/2p1p3/6P1/2PPN3/PB3Q2/1P3P1P/1K1RR3 w - - 0 1 Analysis by Fritz 7: 1.g6 fxg6 2.Ng5 Bd6 3.c5 Bxh2 4.Qh3 h6 5.Nxe6 ± (0.97) Depth: 8/23 00:00:00 149kN 1.g6 fxg6 2.Ng5 Bd6 3.c5 Bxh2 4.Qh3 h6 5.Nxe6 ± (0.97) Depth: 9/25 00:00:00 274kN 1.g6 hxg6 2.Ng5 Bc8 3.Qh3 Bd6 4.Qh7+ Kf8 5.Qh8+ Ke7 6.Qxg7 Ke8 7.Qg8+ Bf8 ± (1.06) Depth: 10/27 00:00:02 1090kN 1.g6 hxg6 2.Ng5 Bc8 3.Qh3 Bd6 4.Qh7+ Kf8 5.Qh8+ Ke7 6.Qxg7 Ke8 7.Qg8+ Bf8 8.c5 ± (1.22) Depth: 11/32 00:00:05 2634kN 1.g6 fxg6 2.Ng5 Re8 3.Qf7+ Kh8 4.Nxh7 Kxh7 5.Re3 Qxh2 6.Rdd3 Qh1+ 7.Ka2 e5 8.Qxd7 ± (1.31) Depth: 12/35 00:00:20 11413kN 1.Nf6+! ± (1.34) Depth: 12/35 00:00:41 22509kN 1.Nf6+! +- (1.63) Depth: 13/34 00:00:52 28645kN 1.Nf6+! +- (1.91) Depth: 13/36 00:01:01 33734kN 1.Nf6+! +- (2.47) Depth: 13/36 00:01:19 44699kN 1.Nf6+! +- (2.75) Depth: 14/41 00:02:16 78521kN 1.Nf6+! +- (3.03) Depth: 14/41 00:03:01 105422kN 1.Nf6+! +- (3.59) Depth: 14/44 00:04:43 166173kN (Celeron 1.2GHz, 832MB hash, 3 & 4 piece EGTB's 27.01.2002) Futility Pruning on New game r2r1bk1/ppqb1ppp/2p1p3/6P1/2PPN3/PB3Q2/1P3P1P/1K1RR3 w - - 0 1 Analysis by Fritz 7: 1.g6 fxg6 2.Ng5 Bd6 3.c5 Bxh2 4.Qh3 h6 5.Nxe6 ± (0.97) Depth: 8/23 00:00:00 147kN 1.g6 fxg6 2.Ng5 Bd6 3.c5 Bxh2 4.Qh3 h6 5.Nxe6 ± (0.97) Depth: 9/25 00:00:00 266kN 1.g6 hxg6 2.Ng5 Bc8 3.Qh3 Bd6 4.Qh7+ Kf8 5.Qh8+ Ke7 6.Qxg7 Ke8 7.Qg8+ Bf8 ± (1.06) Depth: 10/27 00:00:02 1076kN 1.g6 hxg6 2.Ng5 Bc8 3.Qh3 Bd6 4.Qh7+ Kf8 5.Qh8+ Ke7 6.Qxg7 Ke8 7.Qg8+ Bf8 8.c5 ± (1.22) Depth: 11/32 00:00:04 2548kN 1.g6 fxg6 2.Ng5 Re8 3.Qf7+ Kh8 4.Nxh7 Kxh7 5.Re3 Qxh2 6.Rdd3 Qh1+ 7.Ka2 e5 8.Qxd7 ± (1.31) Depth: 12/35 00:00:17 10021kN 1.g6 fxg6 2.Ng5 Bc8 3.c5 Re8 4.Qh3 h6 5.Nxe6 Bxe6 6.Rxe6 Kh7 7.Bc2 +- (1.56) Depth: 13/36 00:00:53 31894kN 1.Nf6+! +- (1.59) Depth: 13/37 00:01:19 47005kN 1.Nf6+! +- (1.75) Depth: 13/37 00:01:26 51122kN 1.Nf6+! +- (2.06) Depth: 13/37 00:01:38 58301kN 1.Nf6+! +- (2.34) Depth: 14/36 00:02:13 79372kN 1.Nf6+! +- (2.63) Depth: 14/37 00:02:48 101145kN 1.Nf6+! +- (3.19) Depth: 14/39 00:06:04 219987kN (Celeron 1.2GHz, 832MB hash, 3 & 4 piece EGTB's 27.01.2002) On January 27, 2002 at 06:20:59, Bas Hamstra wrote: >[D]r2r1bk1/ppqb1ppp/2p1p3/6P1/2PPN3/PB3Q2/1P3P1P/1K1RR3 w - - Nf6!! > >Tao solves this in a couple of minutes (I believe 4 minutes to resolve the fail >high). But with futility pruning turned on it doesn't. I am curious how it >affects Fritz solution time. Fritz and CM see it pretty quick, in about 2 >minutes. > >Best regards, >Bas. > >On January 27, 2002 at 03:59:21, Ernst Walet wrote: > >>On January 26, 2002 at 20:02:29, Bas Hamstra wrote: >> >>>On January 26, 2002 at 16:42:23, Ernst Walet wrote: >>> >>>>On January 26, 2002 at 12:48:46, German Rodriguez wrote: >>>> >>>>>When I click on defaults in the F7 engine parameters, futility pruning is >>>>>enabled as default on my copy. No one has brought this up, so is it just me that >>>>>this happens to? >>>>> >>>>>Won't this do more harm than good in longer time controls and therefore should >>>>>it be left unchecked? >>>> >>>>Yes I noticed it too and futhermore the option for mate extentions is gone. >>>> >>>>I haven't found a position though where this pruning resulted in not finding a >>>>move, or taking much more time. Maybe someone else did? >>>> >>>>Ernst. >>> >>>Try the move Nf6+!! that Ponomariov played with and without. >>> >>>Bas. >> >> >>Can post the position for me, Bas? >> >>Thanks, >>Ernst.
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