Aya traditionally used selective full board search up to 9 plies in 9x9. Search is extended 2 plies when horizon effect occurs. Evaluation function includes string capture search and connections search up to 5 plies (5 plies is 80 rating points stronger than 9 plies version because of fast evaluation function.). Eye recognition and group life and death are static.
It has been extended to use MC methods, and uses 3×3 pattern templates extracted from 10,000 professional games.
Its web site: http://www32.ocn.ne.jp/~yss/
May be downloaded from: http://www32.ocn.ne.jp/~yss/