Hash table in Chinese Chess

Hash table is a very important technique in computer games. With the development of computer Chinese Chess, hash table is wildly used and some of implementations are innovational. Several notable hash table implementations are introduced, some of them being new, while some combing with the specific modification on traditional ones, all considering special characteristics of Chinese Chess. The two common methods, Zobrist hashing and lockless algorithm in parallel search, are also put forward. The experimental results reveal these hash tables are remarkable and essential, significantly improving the overall performance.