From c30cdf2f625a875320aa36a09efb66f54f884b52 Mon Sep 17 00:00:00 2001
From: PaulJeFi <78982620+PaulJeFi@users.noreply.github.com>
Date: Sat, 1 Jun 2024 14:17:27 +0200
Subject: [PATCH] Heavily improving evaluation function

The evaluation is heavily improved in this commit. Ideas come from the internal Scid engine.

With opening book : +70 Elo
Without opening book : +120 Elo
---
 readme.md                  |  4 ++++
 src/JavaScript/reglisse.js | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/readme.md b/readme.md
index 84d099e..381e19d 100644
--- a/readme.md
+++ b/readme.md
@@ -18,6 +18,10 @@ It currently has the following features :
     - [material balance](https://www.chessprogramming.org/Material)
     - [tapered eval](https://www.chessprogramming.org/Tapered_Eval)
     - [Mop-up evaluation](https://www.chessprogramming.org/Mop-up_Evaluation)
+    - [Trapped bisops](https://www.chessprogramming.org/Trapped_Pieces)
+    - [Minor pieces development](https://www.chessprogramming.org/Development)
+    - [Center control](https://www.chessprogramming.org/Center_Control) : [Pawn center](https://www.chessprogramming.org/Pawn_Center)
+    - [Unadvanced central pawns](https://www.chessprogramming.org/Development#Eval_Considerations)
     - [space control eval](https://www.chessprogramming.org/Space) _to be readded_
     - [bishop pair](https://www.chessprogramming.org/Bishop_Pair) _to be readded_
 - [Search](https://www.chessprogramming.org/Search)
diff --git a/src/JavaScript/reglisse.js b/src/JavaScript/reglisse.js
index c6bd09e..db00a28 100755
--- a/src/JavaScript/reglisse.js
+++ b/src/JavaScript/reglisse.js
@@ -1716,6 +1716,7 @@ function evaluate(board) {
         gamePhase = 0,
         piece = 0;
 
+    // PSQT + material
     for (var sq=0; sq<64; sq++) {
         piece = board.board[mailbox64[sq]];
         if (piece != EMPTY) {
@@ -1725,6 +1726,39 @@ function evaluate(board) {
         };
     };
 
+    // Minor pieces developed
+    if (board.board[92] != (WHITE | KNIGHT)) { mg[0] += 8; };
+    if (board.board[93] != (WHITE | BISHOP)) { mg[0] += 8; };
+    if (board.board[96] != (WHITE | BISHOP)) { mg[0] += 8; };
+    if (board.board[97] != (WHITE | KNIGHT)) { mg[0] += 8; };
+    if (board.board[22] != (BLACK | KNIGHT)) { mg[1] += 8; };
+    if (board.board[23] != (BLACK | BISHOP)) { mg[1] += 8; };
+    if (board.board[26] != (BLACK | BISHOP)) { mg[1] += 8; };
+    if (board.board[27] != (BLACK | KNIGHT)) { mg[1] += 8; };
+
+    // Trapped bishop
+    if (board.board[31] == (WHITE | BISHOP)  &&  board.board[42] == (BLACK | PAWN)) { mg[0] -= 120; };
+    if (board.board[38] == (WHITE | BISHOP)  &&  board.board[47] == (BLACK | PAWN)) { mg[0] -= 120; };
+    if (board.board[81] == (BLACK | BISHOP)  &&  board.board[72] == (WHITE | PAWN)) { eg[1] -= 120; };
+    if (board.board[88] == (BLACK | BISHOP)  &&  board.board[77] == (WHITE | PAWN)) { eg[1] -= 120; };
+
+    // Central pawn control
+    if ((board.board[64] == (WHITE | PAWN)  ||  board.board[54] == (WHITE | PAWN)) &&
+        (board.board[65] == (WHITE | PAWN)  ||  board.board[55] == (WHITE | PAWN))) {
+        mg[0] += 15;
+    };
+    if ((board.board[64] == (BLACK | PAWN)  ||  board.board[54] == (BLACK | PAWN)) &&
+        (board.board[65] == (BLACK | PAWN)  ||  board.board[55] == (BLACK | PAWN))) {
+        mg[1] += 15;
+    };
+
+    // Undevelopped central pawn
+    if (board.board[84] == (WHITE | PAWN)  &&  board.board[74] != EMPTY) { mg[0] -= 15; };
+    if (board.board[85] == (WHITE | PAWN)  &&  board.board[75] != EMPTY) { mg[0] -= 15; };
+    if (board.board[34] == (BLACK | PAWN)  &&  board.board[44] != EMPTY) { mg[1] -= 15; };
+    if (board.board[35] == (BLACK | PAWN)  &&  board.board[45] != EMPTY) { mg[1] -= 15; };
+
+
     var side2move = board.turn ? 0 : 1;
 
     var mgScore = mg[side2move] - mg[side2move ^ 1],