> > With 8 hashes per position, the chance of two different boards > > producing a different set of hashes but > > the same canonical hash is greater than 1/2^64, because there will be > > a bias in the choice of canonical > > hashes - toward numerically lower numbers, for instance. > > > > I think. > > More importantly, how does it differ from 8/2^64 = 1/2^61?
If hash collisions are worrisome, you can always use 96-bit or 128-bit hashes. Modern x86s can do 8 parallel loads, adds, subtracts, or stores of 16-bit numbers in one step using SIMD, just like Antti Huima suggests in http://fragrieu.free.fr/zobrist.pdf. Michael Wing _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
