- The ball is outside the wrist
- Humereus/torso angle is > 90 degrees
- The landing foot "crosses over" the front of the pivot foot
- Stepping backward (rocking) with the non pivot foot
1. The ball is outside the wrist (the humereus has been turned clockwise in order to allow the palm to face away (thumb up) from the body. (95% of the illegal issues).
2. The humereus/torso angle is greater than 90 degrees. 95% of the time when this occurs, # 1 is occurring as well. However, I have seen Converted Wind Mill pitchers “mask” # 1 by turning their body on the back swing so that the palm is down. It appears as if the ball is not outside the wrist.
3. The landing foot crosses over the imaginary line from the front of the pivot foot to home plate.
4. Stepping backwards and losing contact with the rubber, with the non pivot foot is not allowed.
