[halfcat]

What separates one chess engine from another is its ability to efficiently navigate and evaluate the game tree. Stockfish effectively discards probably 95% or more of the nodes in any position. Easier said than done, better not discard the best move in that 95%. Evaluation is relatively simple, a fancy lookup table. They say love covers a multitude of sins. Well, searching one move deeper than your opponent covers a multitude of static positional evaluation mistakes. Searching deeper can figure out the complexity of the position better than anything that can be statically evaluated. That's where virtually all improvements exist today, figuring out which moves can be safely discarded.