One of the finishing touches on putting more distance, consistency and accuracy into your golf game is understanding the rule of the target and the target swing over drill.
Begin by taking your normal stance. Then pick the club up so the club head is just over the ball. Initiate a backswing by slowly swinging the club back. Mimic the regular swing as much as possible in regards to body movement. Start the takeaway with only your arms and shoulders. Once your arms and club are extended back allow your hips to rotate. During the forward swing, allow your arms and body to work cohesively. Similar to a regular swing your body will turn towards the target. Follow through to a finish position flat on your left foot, belt buckle facing your target and right heel off the ground. The idea is to create a flatter swing plane. You are essentially swinging the club parallel to the ground throughout the entire drill. Capture the feeling of swinging flatter and then try to make a flatter swing at the golf ball.
There are many causes to an over the top downswing. A flat backswing can lead to a steep downswing. The baseball swing drill will not help correct a flat backswing. However, it will help create a better swing plane. Remember, the swing should model a flatter plane rather than a steep swing plane. A steep downswing is similar to a movement such as chopping wood. The swing should go around your body rather than up and down.