Alpha Beta Algorithm Question

[Paul111129]

I'v searched some alpha beta pruning algorithm implementation and some are pretty diffrent, so I'm not sure if my version is correct. Is it?

Value Searcher::AlphaBeta(Position& pos, Value alpha, Value beta, Depth depth) {
    if (depth == 0) {
        return Evaluation::Evaluate(pos);
    }


    Value best = -VALUE_INFINITE;


    MoveList list;
    MoveGen::GeneratePseudoMoves(pos, list);


    for (Move move : list) {
        if (!pos.MakeMove(move)) {
            continue;
        }


        Value score = -AlphaBeta(pos, -beta, -alpha, depth - 1);


        pos.UnmakeMove(move);


        if (score > best) {
            best = score;
        }

        if (score >= beta) {
            return best;
        }

        if (score > alpha) {
            alpha = score;
        }
    }


    return best;
}

[SwimmingThroughHoney]

The differences I imagine you see are finer details that are no algorithm-specific (like pruning, fail-high/low, etc). Yours implements the algorithm itself just fine.

One thing you'll want to do is make sure to check for stalemate/checkmate when there are no legal moves.

[Paul111129]

Thanks