Author: Severi Salminen
Date: 13:46:17 12/05/00
Hi!
Check out this position:
[D]rnbqkbnr/ppp2ppp/8/3pp3/3PP3/8/PPP2PPP/RNBQKBNR w
With futility pruning my program does this:
Time Depth Score Nodes PV
0 1 -0.14 175 Be3
0.00 2 -0.19 1851 Be3 Be6
0.11 3 -0.11 7755 Nf3 Bb4+ Bd2 dxe4 Bxb4 exf3 dxe5 Qxd1+ Kxd1
fxg2 Bxg2
0.33 4 -0.14 22227 Nf3 exd4 Qxd4 Be6
0.98 5 0.00 67477 dxe5 dxe4 Qd7+ Qxd7
3.07 6 -0.12 324618 Nf3 Bg4 Be2 Bxf3 Bxf3 Bb4+
12.41 7 0.00 1515184 Qh5 dxe4 Qxe5+ Qe7 Qxc7 Qxc7
33.06 8 -0.09 4203195 dxe5 dxe4 Qxd8+ Kxd8 Bc4 Nc6 Bf4 Bb4+
And without:
Time Depth Score Nodes PV
50 1 -0.14 175 Be3
0.05 2 -0.19 1851 Be3 Be6
0.16 3 -0.11 7850 Nf3 Bb4+ Bd2 dxe4 Bxb4 exf3 dxe5 Qxd1+ Kxd1
fxg2 Bxg2
0.44 4 -0.14 22555 Nf3 exd4 Qxd4 Be6
1.10 5 -0.09 73064 Nf3 dxe4 Nxe5 Bb4+ c3
2.85 6 -0.12 306521 Nf3 Bg4 Be2 Bxf3 Bxf3 Bb4+
9.61 7 -0.07 1212161 dxe5 dxe4 Qxd8+ Kxd8 Bc4 Bb4+ Nd2
29.33 8 -0.09 3947537 dxe5 dxe4 Qxd8+ Kxd8 Bc4 Nc6 Bf4 Bb4+
Why the h?%l is the one without futility pruning faster and has less nodes? I
use futility margin of 2 pawns.
My futility code is something like: (I prune check now also...)
if(depth==1)
if(futility_condition(Moves[k].value)<=alpha)
continue;
the futility_condition() returns the current material balance + the material
gain of the move+ 200.
Any ideas?
BTW. Does my node counts look reasonable? I'm using MVV/LVA ordering in qsearch
+ nullmoves (R=2).
Severi
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