Author: Daniel Clausen
Date: 11:56:39 09/12/99
Hi
I'm trying to use Eugenes EGTBs in my own chess engine and downloaded
the file tbgen.zip from Mr. Hyatts site.
I have the following simple test position:
4k3/8/4K1R1/8/8/8/8/8/ w - -
WK=E6, WR=G6, BK=E8, white to move
Now this should be mate in 1 in my opinion. :) But when I probe EGTB I
get the value 32767. I tried it with similar positions and always got
the same value.
I'm not sure whether it already fails during index-calculation or while
probing.
Indexing
--------
index = PfnIndCalcFun(iTb, stm) (wpP, bpP, epSquare, fInvert);
When I call this function, the parameters are set as follows:
iTb = 4
stm = 0
wpP = <pointer to squares of white pieces>
bpP = <pointer to squares of black pieces>
epSquare = 127
fInvert = 0
I think the wpP and bpP are correct, because the macros produce the following
output:
SqFindKing(wpP) = 44
SqFindKing(bpP) = 60
SqFindOne(wpP, 4) = 46
And with these parameters the resulting index I get is 22247.
Can anyone reproduce this index by chance?
Lookup
------
tbScore = L_TbtProbeTable(iTb, stm, index);
where iTb = 4
stm = 0
index = 22247
==> tbScore = 32767
I'd be happy if anyone could tell me whether the index is already broken or
only the resuling score.
cu,
-sargon
PS. I hope I didn't make any silly copy/paste errors...
PPS. I created the TBs myself and compared them to what's available on
Mr Hyatts website - and they were identical.
PPPS. I tried to reproduce the above things with Crafty, but unfortunately
Crafty prefers to hang in InitializeAttackBoards() instead. I'm running
Linux but on PPC, so.. that could explain this weird behaviour... *shrug*
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