Late Move Reductions (LMR) is a non-game specific enhancement to the alpha-beta algorithm and its variants which attempts to examine a game search tree more efficiently. It uses the assumption that good game-specific move ordering causes a program to search the most likely moves early. If a cut-off is going to happen in a search, the first few moves are the ones most likely to cause them. In games like chess, most programs search winning captures and "killers" first. LMR will reduce the search depth for moves searched later at a given node. This allows the program to search deeper along the critical lines, and play better.