Chinese Chess (Xiangqi) in TypeScript

NOTICE: It is a proof-of-concept project. The evaluator is weak, and currently there are no advanced method such as Quiescence Search.

A project of Chinese Chess with AI based on HTML5/canvas and TypeScript. Here is a demo.

There are several Search Engines.

• a very navie algorithom is minimax search
• negamax, which is a common way of implementing minimax
• minimax search with alpha–beta pruning
• negamax search with alpha–beta pruning (fail hard)
• fail soft alpha-beta algorithm
• a simple aspiration search based on fail-soft alpha-beta search
• PVS (Principal Variation Search)
• NegaScout (almost the same with PVS, sometime just another name of PVS)
• NegaScout with transposition table and history heuristic enhancement
• MTD(f), Memory-enhanced Test Driver with node n and value f
• iterative deepening version of fail-hard alpha-beta algorithm (using time limitation)
• iterative deepening version of PVS (using time limitation)
• iterative deepening version of NegaScout with transposition table and history heuristic enhancement

Here,

• history husrestic (Assumption: If a move is good, then the next several moves are also good)
• transposition table using Zobrist hash (In lots of cases, moves are independent and communitive)
• iterative deepening search using time limitation (not fixed search depth, but depends on time cost)