For years, 43 inches was the standard length of a driver. Now, the driver you buy from the store is more than 45 inches—which is designed to help you hit it farther. But the longer the club gets, the less responsive it is to your effort to make it swing. Choking up on the handle like Brooke Henderson is doing brings the balance point closer to your hands and increases the response you get to your swinging effort. Just be careful not to choke up too much, because you start to lose response again.