Keep your left wrist (right for lefties) flat at the top
Golf Tips By Cameron Rankin
One of the secrets to hitting straighter golf shots more often is the left wrist position (the right wrist for lefties) at the top of the back swing. Assuming your fundamentals are correct, this position can be achieved fairly easily. During your backswing, your wrists hinge on an approximate angle of 45 degrees to the ground; the shaft of the club should also be on this angle. Turning your shoulders to complete the backswing, you should still have your left wrist flat. Cupping your left wrist will cause you to slice the ball to the right of your target. Arching your left wrist will cause your ball to fly low and left of your intended target. The arched left wrist is not very common, as golfers like to see the ball have some trajectory. Check your left wrist position for lower and more consistent scores.