Author: Robert Hyatt
Date: 05:16:34 11/14/97
Go up one level in this thread
On November 14, 1997 at 04:15:24, Chris Whittington wrote: > >On November 14, 1997 at 03:30:27, Andreas Mader wrote: > >>Chris has claimed many times that his CSTal only searches 4000 NPS and >>performed very well in Paris, whereas the 'fast searchers' (>100 >>KiloNPS) had their problems. >> >>This is of course true, but it leads to a question: How do you count the >>NPS? I don't know if this has been asked before, but I would like to >>know, how different programs are counting NPS. Can it be that Chris is >>simply the 'king of understatement' because he uses a different >>algorithm? > >I'm pretty sure I count in the standard way; here my method, Bob or >whoever can say if its standard or not ..... > >CSTal tree searches, like everybody else. > >At each node it does the following: > > >makemove >evaluate >if (extend_this_node) >{ > do a hash lookup - it might find a mtach and cutoff here > go one more deeper, recursively and return back to here >} >unmakemove >if score>alpha etc > >the above process count for ONE node. >if the hash finds a cutoff it still counts for ONE node >if the node gets extended then we add more nodes by the same process > basically my search/quiesce functions look like this: int search() { nodes_searched++; ... } so I think we are counting the same thing. > >>If you find a position in the hash tables, do you count it? > >yes, as one node, as described above ditto here, because the nodes_searched is incremented upon entry to search, *then* I do the hash probe and a successful one will return with no further searching. I do *not* count the nodes that the hash hit replaces, because I don't store that info in the table (although I suppose I could.) > >>If a position has a 'clear' material balance so that you do not need to >>do some 'fine tuning' in the evaluation function, do you count it? > >CSTal doesn't do a lazy eval, since the eval function can produce very >large scoring swings. Only MATERIALISTS do lazy evals :) you *could* do one. IE how big a positional score can you produce? I can produce one of up to at *least* +/- 10 pawns, and in simple endings +/- 20 pawns... It only means as the circumstances change, I begin to be less "lazy". This is why, on a P6/200, I search 60K in the opening, 80-100K in the middlegame, and 120K in the endgame. Because I have to get less lazy as the game progresses because positional scores can get bigger and bigger... > >So not applicaple. > >>When you do quiescence search, do you count the NPSs? > >CSTal doesn't work to this MATERIALISTIC algorithm. Any node, extension >or whatever you want to call it gets counted. > >>etc. etc. >> >>Could it be that the 'real' factor between knowledge based programs and >>fast searchers is not that big (4000 : 200.000)? > >Don;t think so, but comments welcome .... > >Chris > >> >>Best wishes >>Andreas
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