private ValuedMove AlphaBetaMove(GameState state, AlphaBetaTreeNode node, int alpha, int beta)
        {
            if (state.IsFinal)
                return state.Leaf(Evaluate(state, false), node);

            var curr = new ValuedMove(Int32.MinValue);
            foreach (var pos in state.Grid.FreeGrid)
            {
                var newNode = node == null ? null : node.AddChild("Put in " + pos);
                var minCheck = AlphaBetaPick(state.Move(pos), newNode, alpha, beta);
                curr.CheckSmaller(minCheck, pos);
                if (curr.BetaPrune(beta, node)) return curr;
                if (curr.Value == 1000) return curr;
                alpha = Math.Max(alpha, curr.Value);
            }

            if (node != null) node.Value = curr.Value.ToString();
            return curr;
        }

        private ValuedMove AlphaBetaOpponentMove(GameState state, AlphaBetaTreeNode node, int alpha, int beta)
        {
            if (state.IsFinal)
                return state.Leaf(Evaluate(state, true), node);

            var curr = new ValuedMove(Int32.MaxValue);
            foreach (var pos in state.Grid.FreeGrid)
            {
                var newNode = node == null ? null : node.AddChild("Put in " + pos);
                var maxCheck = AlphaBetaOpponentPick(state.Move(pos), newNode, alpha, beta);
                curr.CheckLarger(maxCheck, pos);
                if (curr.AlphaPrune(alpha, node)) return curr;
                if (curr.Value == -1000) return curr;
                beta = Math.Min(beta, curr.Value);
            }

            if (node != null) node.Value = curr.Value.ToString();
            return curr;
        }

        private ValuedMove AlphaBetaPick(GameState state, AlphaBetaTreeNode node, int alpha, int beta)
        {
            if (state.IsFinal)
                return state.Leaf(Evaluate(state, true), node);

            var curr = new ValuedMove(Int32.MinValue);
            foreach (var piece in state.RemainingPieces)
            {
                var newNode = node == null ? null : node.AddChild("Selected " + piece);
                var minCheck = AlphaBetaOpponentMove(state.Piece(piece), newNode, alpha, beta);
                curr.CheckSmallerPiece(minCheck, piece);
                if (curr.BetaPrune(beta, node)) return curr;
                if (curr.Value == 1000) return curr;
                alpha = Math.Max(alpha, curr.Value);
            }

            if (node != null) node.Value = curr.Value.ToString();
            return curr;
        }

        private ValuedMove AlphaBetaOpponentPick(GameState state, AlphaBetaTreeNode node, int alpha, int beta)
        {
            if (state.IsFinal)
                return state.Leaf(Evaluate(state, false), node);

            var curr = new ValuedMove(Int32.MaxValue);
            foreach (var piece in state.RemainingPieces)
            {
                var newNode = node == null ? null : node.AddChild("Selected " + piece);
                var maxCheck = AlphaBetaMove(state.Piece(piece), newNode, alpha, beta);
                curr.CheckLargerPiece(maxCheck, piece);
                if (curr.AlphaPrune(alpha, node)) return curr;
                if (curr.Value == -1000) return curr;
                beta = Math.Min(beta, curr.Value);
            }

            if (node != null) node.Value = curr.Value.ToString();
            return curr;
        }