I analyzed the board and noticed that our pieces already form a strong base in column 4. We have an O at row5, col4 and an O at row4, col4. By playing in column 4, our piece will land at row3, col4, creating a vertical threat with three O’s in a row. This forces the opponent to address our upcoming win (as the next move in column 4 would complete four), while not giving them any immediate winning opportunities. Thus, column 4 is the best move to press our advantage.