You're Correct!

Understanding the position that you need to achieve with your wrists at the top of your back swing will really help you improve your accuracy and get you hitting shots much closer to the target.

Your wrist position at the top of your back swing influences the club face position. If your wrist position is correct then the club face is square to the target and if you return it back down to the golf ball from this position, the face will be aiming at the target as it strikes the golf ball and you will hit a straight shot directly at the target if you swing the club head along the target line.

The ideal position for your wrists to be in at the top of your back swing, if you are a right handed golfer, is to have your left wrist flat and in line with your left forearm. This will put your right wrist into a position that you would see if you held a tray above shoulder high, with your palm under the tray. Your right wrist will be bent backwards with your palm upwards towards the sky.

If you achieve a position where your left wrist is cupped, when the back of your left hand is vertical so that there is an upward curve in your left wrist, then the club face is open and if you return the club head back down to the ball from this position, then the club face will be aiming to the right of the target. This will now produce golf shots that miss right on the target.

If your left wrist at the top of your back swing is arched, that is bent over away from you so that the back of your left hand is horizontal and skywards, then the club face is now shut or closed. Returning the club head back to the golf ball from this position, will result in the club face returning to the ball aiming left of the target. This will now produce a golf shot that finishes left of the target.

Arching your left wrist is not the correct position that you want to achieve if you are going to hit consistent straight golf shots at the target. An arched left wrist will produce golf shots that fly left of the target as the club face is closed.

If you cup your left wrist at the top of your back swing, then the club face is open, and swinging back down towards the golf ball from this position will result in golf shots that fly right of the target.

If you keep both your left wrist flat and your right wrist flat as well at the top of your back swing then you will not have set your wrists correctly. You need to have a flat left wrist but a bent right wrist to achieve a position in your right wrist as though you are holding a tray up above your shoulder.