This late movement at release, as the pitcher goes from an upright posture into a more tilted “B” or “C” posture is bad for multiple reasons. First, this late movement/disconnect is not good for the health of the arm. Late disconnects can cause extra stress on the elbow and/or shoulder because of the sideways movement generated and often can cause a banging out of the arm to occur. Additionally, command/control will be decreased. Because of this drastic last second change in positions, the release point is very tough to replicate making it hard for the pitcher to continuously hit his spots. Last, the pitcher loses efficiency because of the late sideways movement, which takes away from the momentum and energy that is being placed behind the ball.
If you are a coach or player and are dealing with/have a “B” or “C” posture, the key is to try and get into this posture as early as possible so that you can maintain the angle/tilt throughout the delivery. This type of pre-setting can be done in the set position or early into leg lift so that as momentum toward home plate increases the pitcher is already in his natural posture. This will keep prevent a late disconnect, thereby improving arm health, command, and velocity.