voroskoi/pistike - Change BQP2M5YIF2R53XJSJXTZRSXMOAJ4UEJBCLFCZ2OHF27T4DOGWJJQC

Implement TT mating scores

Created by voroskoi on January 31, 2023

BQP2M5YIF2R53XJSJXTZRSXMOAJ4UEJBCLFCZ2OHF27T4DOGWJJQC

Dependencies

In channels

main

Change contents

Insertion in src/eval.zig at line 4 [5.33]

[4.3543]

[5.78]


// Scoring layout:
// -infinity, -MATE_VALUE, -CHECKMATE_SCORE, score, CHECKMATE_SCORE, MATE_VALUE, infinity

Replacement in src/eval.zig at line 8 [5.33]

B:BD[5.79] → [6.0:36]

pub const CHECKMATE_SCORE = -49000;

[5.79]

[6.36]

pub const INFINITY = 50_000;
pub const MATE_VALUE = 49_000;
pub const CHECKMATE_SCORE = 48000;

Replacement in src/Transposition.zig at line 17 [3.354]
B:BD[3.677] → [3.677:695]
```
    value: isize,
```
[3.677]
[3.695]
```
    score: isize,
```
Replacement in src/Transposition.zig at line 45 [3.354]
B:BD[3.1358] → [3.1358:1386]
```
                .value = 0,
```
[3.1358]
[3.1386]
```
                .score = 0,
```
Replacement in src/Transposition.zig at line 73 [3.354]
B:BD[3.2021] → [3.2021:2044]
```
        .value = 3000,
```
[3.2021]
[3.2044]
```
        .score = 3000,
```

Replacement in src/Transposition.zig at line 81 [3.354]

B:BD[3.2185] → [3.2185:2237]

    try std.testing.expectEqual(got.?.value, 3000);

[3.2185]

[3.2237]

    try std.testing.expectEqual(got.?.score, 3000);

Replacement in src/Search.zig at line 100 [9.35]

∅:D[7.1232] → [8.4080:4140]

B:BD[8.4080] → [8.4080:4140]

        const ALPHA = -25_000;
        const BETA = 25_000;

[7.1232]

[10.184]

        const ALPHA = -eval.INFINITY;
        const BETA = eval.INFINITY;

Insertion in src/Search.zig at line 164 [9.35]

[9.1248]

[8.5945]

    inline fn adjustTTgetScore(self: *const @This(), s: isize) isize {
        if (s < -eval.CHECKMATE_SCORE) {
            return s + @intCast(isize, self.ply);
        } else if (s > eval.CHECKMATE_SCORE) {
            return s - @intCast(isize, self.ply);
        } else {
            return s;
        }
    }
    inline fn adjustTTsetScore(self: *const @This(), s: isize) isize {
        if (s < -eval.CHECKMATE_SCORE) {
            return s - @intCast(isize, self.ply);
        } else if (s > eval.CHECKMATE_SCORE) {
            return s + @intCast(isize, self.ply);
        } else {
            return s;
        }
    }

Insertion in src/Search.zig at line 185 [9.35]

[8.6036]

[11.1809]

        // TT probe
        if (self.ply != 0) {
            if (self.tt.get(self.state.hash)) |entry| {
                if (entry.depth >= depth_orig) {
                    switch (entry.flag) {
                        .empty => unreachable,
                        .exact => return self.adjustTTgetScore(entry.score),
                        .lower => {
                            if (entry.score <= alpha_orig) return self.adjustTTgetScore(alpha_orig);
                        },
                        .upper => {
                            if (entry.score >= beta) return self.adjustTTgetScore(beta);
                        },
                    }
                }
            }
        }

Deletion in src/Search.zig at line 223 [9.35]

B:BD[3.2627] → [3.2627:3163]

∅:D[12.278] → [9.1780:1781]

∅:D[3.3163] → [9.1780:1781]

∅:D[8.6566] → [9.1780:1781]

B:BD[9.1780] → [9.1780:1781]

        // TT probe
        if (self.tt.get(self.state.hash)) |entry| {
            if (entry.depth >= depth_orig) {
                switch (entry.flag) {
                    .empty => unreachable,
                    .exact => return entry.value,
                    .lower => {
                        if (entry.value <= alpha_orig) return alpha_orig;
                    },
                    .upper => {
                        if (entry.value >= beta) return beta;
                    },
                }
            }
        }

Insertion in src/Search.zig at line 231 [9.35]
[8.6832]
[2.41]
```
                self.ply += 1;
```
Insertion in src/Search.zig at line 245 [9.35]
[8.7066]
[13.451]
```
                self.ply -= 1;
```

Replacement in src/Search.zig at line 297 [9.35]

B:BD[8.8434] → [8.8434:8486]

                    self.ply >= REDUCTION_LIMIT and

[8.8434]

[8.8486]

                    depth >= REDUCTION_LIMIT and

Replacement in src/Search.zig at line 302 [9.35]

B:BD[8.8687] → [8.8687:8764]

                    scr = -try self.negamax(-alpha - 1, -alpha, depth -| 3);

[8.8687]

[8.8764]

                    scr = -try self.negamax(-alpha - 1, -alpha, depth -| 2);

Deletion in src/Search.zig at line 331 [9.35]

B:BD[9.2296] → [8.10143:10211]

B:BD[8.10211] → [3.3281:3498]

∅:D[3.3498] → [8.10211:10457]

B:BD[8.10211] → [8.10211:10457]

∅:D[14.2325] → [9.2343:2344]

∅:D[8.10457] → [9.2343:2344]

B:BD[9.2343] → [9.2343:2344]

B:BD[9.2344] → [8.10458:10529]

∅:D[8.10529] → [15.1158:1173]

B:BD[15.1158] → [15.1158:1173]

            // fail-hard beta cutoff
            if (scr >= beta) {
                self.tt.set(.{
                    .key = self.state.hash,
                    .value = beta,
                    .depth = @intCast(u8, depth),
                    .flag = .upper,
                });
                // store killer moves
                if (!mp.move.capture) {
                    score.killer_moves[1][self.ply] = score.killer_moves[0][self.ply];
                    score.killer_moves[0][self.ply] = mp.move;
                }
                // node (move) fails high
                return beta;
            }

Insertion in src/Search.zig at line 356 [9.35]

[15.1838]

[9.2715]


                // fail-hard beta cutoff
                if (scr >= beta) {
                    self.tt.set(.{
                        .key = self.state.hash,
                        .score = self.adjustTTsetScore(beta),
                        .depth = @intCast(u8, depth),
                        .flag = .upper,
                    });
                    // store killer moves
                    if (!mp.move.capture) {
                        score.killer_moves[1][self.ply] = score.killer_moves[0][self.ply];
                        score.killer_moves[0][self.ply] = mp.move;
                    }
                    // node (move) fails high
                    return beta;
                }

Replacement in src/Search.zig at line 382 [9.35]

B:BD[8.11594] → [8.11594:11667]

                return eval.CHECKMATE_SCORE + @intCast(isize, self.ply);

[8.11594]

[8.11667]

                return -eval.MATE_VALUE + @intCast(isize, self.ply);

Replacement in src/Search.zig at line 390 [9.35]

B:BD[3.3645] → [3.3645:3673]

            .value = alpha,

[3.3645]

[3.3673]

            .score = self.adjustTTsetScore(alpha),

Insertion in src/Search.zig at line 407 [9.35]

[8.12114]

[9.4101]


        // avoid overflow of self.ply arrays
        if (self.ply > MAX_PLY - 1) {
            return EVAL_FUNCTION(self.state);
        }

Replacement in src/Search.zig at line 430 [9.35]

B:BD[3.3882] → [3.3882:3928]

                .exact => return entry.value,

[3.3882]

[3.3928]

                .exact => return self.adjustTTgetScore(entry.score),

Replacement in src/Search.zig at line 432 [9.35]

B:BD[3.3956] → [3.3956:4026]

                    if (entry.value <= alpha_orig) return alpha_orig;

[3.3956]

[3.4026]

                    if (entry.score <= alpha_orig) return self.adjustTTgetScore(alpha_orig);

Replacement in src/Search.zig at line 435 [9.35]

B:BD[3.4073] → [3.4073:4131]

                    if (entry.value >= beta) return beta;

[3.4073]

[3.4131]

                    if (entry.score >= beta) return self.adjustTTgetScore(beta);

Deletion in src/Search.zig at line 460 [9.35]

B:BD[8.12914] → [8.12914:13068]


            // fail-hard beta cutoff
            if (scr >= beta) {
                // node (move) fails high
                return beta;
            }

Insertion in src/Search.zig at line 465 [9.35]

[8.13214]


                // fail-hard beta cutoff
                if (scr >= beta) {
                    // node (move) fails high
                    return beta;
                }

Insertion in README.md at line 113 [17.34]

[3.4293]

[16.126]

[Transposition Table Scoring](https://raw.githubusercontent.com/maksimKorzh/chess_programming/master/src/bbc/tt_search_mating_scores/TT_mate_scoring.txt)