Add LMR

src/search/negamax.rs

@@ -102,11 +102,16 @@ pub fn negamax(
         let score = if legal_moves == 1 {
             -negamax(game, -beta, -alpha, depth - 1, plies + 1, time, nodes, true)?
         } else {
+            let mut lmr_reduction = 0;
+            if !in_check && !mv.is_capture() && depth > 2 && legal_moves > 3 {
+                lmr_reduction = 2;
+            }
+
             let mut score = -negamax(
                 game,
                 -alpha - 1,
                 -alpha,
-                depth - 1,
+                depth - 1 - lmr_reduction,
                 plies + 1,
                 time,
                 nodes,