Arasan 11.6

[jdart]

Arasan 11.6 is available from http://www.arasanchess.org. This is basically the same version that played in the recent ACCA Pan-American tournament.

Changes in Arasan 11.6 (Nov. 2009):
1) Several speed improvements:
a. Greater use of lazy eval + partial evals are now cached.
b. Best move and score in eval cache can be independently updated.
c. Eval cache is shared across threads.
d. better alignment/sizing of structures
2) Scoring changes:
a. Bishop pair bonus decreased a bit
b. Mobility scores tweaked
c. Outpost scoring tweaked
d. Some king safety changes esp. for enemy pawns near King
3) Search changes:
a. Now using variable reduction null move again.
b. Allow reduce/prune on moves regardless of history, except the
two moves with best history are exempt.