The importance of one-handed golf drills
When you practice one-handed golf, you are weakening your swing system my removing one arm, which allows you to sharpen and polish your shot control as the club comes down. When hitting one-handed, your brain is awakened to the fact that it should not add muscle when the club is coming down. Path integrity is hard enough to maintain two-handed, but without the support of the other stabilizing arm: this becomes a more delicate procedure. If one-handed you try to strike the ball instead of letting the swing pick up the ball, it would cause the swing path to be violated causing a miss-hit. You should feel as if you are ‘slinging’ the ball with the clubface instead of actually hitting it.
When you are practicing with each arm alone it is important to change it up after each swings. First hit a shot left-handed, then right-handed, then double-handed and then repeat. This is important because it discourages the brain from compensating for the use of excessive power when two-handed and essentially regulates the use of muscle in all three modes.
A highly trained player can hit a perfect shot one-handed, with each arm and can also work in draws and fades. To get this level of accuracy requires some considerable practice, however it goes a long way in developing the perfect swing technique.