Wrist rolling occurs during a baseball or softball swing when the batter allows his top hand to come over the top of the bottom hand in the middle of the swing, causing the batter to consistently hit the ball on the ground. There are several potential causes for this flawed hitting mechanic that can be corrected through proper practice and drills.
A great baseball swing always starts with the correct grip. Many inexperienced players will wrap their hands tightly around the bat, causing the wrists to roll at the wrong time in the swing.
Set up a hitting tee and a net to catch the hit balls. Before the player starts to take swings, have her get in her batting stance and take a look at how she is gripping the bat. Ideally, the door-knocking knuckles of both hands should be lined up. The bat handle should rest in the fingers, not the palms of the hand.
After correcting her grip, have the player take several swings at a ball placed on the tee. It is important to use a hitting tee to correct these kinds of flawed hitting mechanics rather than live pitched balls as it allows the hitter to concentrate fully on the skill she is trying to perfect.
Inadequate wrist strength can also lead to a hitter rolling his wrists during the swing. A good way for a player to strengthen his wrists is to stand with one arm straight out in front of his body, parallel to the ground. He would then hold a bat in his hand, pointing it straight up in the air. Have him slowly rotate the bat to the right and then left, stopping when it is parallel to the ground. Do this about 10 times for each wrist.
A coach needs to emphasize the need to keep the top hand of the bat facing upward through the middle part of the swing. Have the player take a practice swing, stopping at the midpoint of the swing, and observe her hand position. If the top hand is facing downward, show her the proper hand position at this point of the swing, then have her continue to take practice half swings until she can replicate the proper position.
It is likely that once a player moves on from half swings to a full swing that the wrist rolling will creep back into the swing. Make sure other players and coaches are a safe distance away. Have the player use a very light bat (a tee ball bat works well), and tell her to go ahead and take a full swing, paying attention to keeping the top hand facing up through the middle portion of the swing. At what would be the contact portion of the swing, have her release the bat with the goal being to throw it as far as she can. This should teach proper hand position and assist the batter in getting the feel of throwing her hands during the swing.