You are moving you feet as the ball is coming this will cause you to be out of position .getting in position early with you weight back on you base foot. It's easy to slide your base foot along the base.just had lesson with player using you mechanics.missed balls over his head because he did not have time to bring his stride foot back in to a jumping position. Thanks
why even put your studs on the bag at all and just make sure your heal is on a corner or the middile