Author: Uri Blass
Date: 11:14:13 10/07/03
Go up one level in this thread
On October 07, 2003 at 13:27:30, Russell Reagan wrote: >On October 07, 2003 at 13:08:28, Anthony Cozzie wrote: > >>I'm sorta disappointed, actually. > >YOU could always make the statement :) > > >>I think I said that it was harder with bitboards ;) However, it is not exactly >>_easy_ to write in any representation. >> >>The logic runs like this: A big part of capture evaluation is xray: if I have >>Ba1 + Qb2, my pawn at e5 is defended twice, not once. With bitboards, figuring >>this stuff out is very annoying, because get_attacks_bishop(E5) will not find >>the bishop. To make things even more annoying, imagine Pf6, Pe5, Qb2, and Ba1 - >>now we have to deal with pawns as well. With a 64 byte or 0x88 board, you just >>keep scanning. This is why Zappa's capture evaluation actually doesn't use the >>bitboards (slight fib, but mainly it scans). > >I was going to recommend that you could still do scanning quite easily using >bitboards, and it shouldn't need to be any slower than an 0x88 approach, if you >are careful. > > >>I'm working on incremental attack >>tables right now so that I don't have to mess with it. > >Be sure that you can really benefit from the overhead involved, because when you >go incremental, you have that overhead no matter what. If you do things on the >fly, you save work in cases where you don't need it. I know several people >prefer to do things on the fly, but I don't know of anyone that has tried both >ways and uses the incremental approach, but I certainly don't know what everyone >does. I already have some incremental stuff for directions of attack(not for pieces) and I decided against more incremenrtal stuff and I decided that functions are better. I think that the main problem with incremental stuff is that it does other things slower. The problem is that if you use arrays often you cannot use the L1 memory for other things that may be more important. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.