You can't hit the fairway, even when make a good swing.
Why it's happening
Your grip is making it difficult to square the clubface at impact.
How to fix it
Insert two tees in the creases formed at the base of your thumbs as shown and check how they line up.
Your grip is bad if...
One tee points to the right of your grip and the other points to the left. This mismatch of strong and weak holds creates opposing forces in your hands and limits their ability to square up the clubface and release the club with authority.
Your grip is good if...
The tees form a vertical line. When your hands are aligned like this they can work in the same direction as a single unit and deliver the clubhead to the ball with maximum power. That means more yards with the sameor even lesseffort. However you place your hands on the handle, make it your goal to "unify" them every time.
• If you slice, line up the tees over the right side of the grip. This gives you more power to square up the face and make contact on the sweet spot.
• If you hook, line up the tees over the left side of the grip. This weak hold keeps the face from closing too quickly and hooking the ball left. It's good for hitting a power fade.