emmett16 is right. Uppercut swings produce a lot of groundouts because the bat is not on the same plane as the ball for very long. The best swing stays on the same plane as the ball for a longer time. This will produce contact that creates backspin on the ball which makes it carry. That Ted Williams book is one of the best hitting books ever written.
Oddly enough even though I like his swing it's so fast he has very little bat control. He needs to work on making contact first. Then look for power and pulling the ball.