To throw under the arm, you cross your arms, one on top of the other, and throw an object from the lower hand. Catching under the arm is the same thing in reverse: crossing your arms and catching an object in the lower hand.
In a windmill, one hand does every throw under the arm and the other hand does outside throws. In a cross-armed pattern, one hand does every throw and every catch under the arm. In Mike's mess, both hands do every throw and every catch under the arm. To do a wrist drop, you start with your arms crossed, drop an object down from the hand on top, uncross your arms and re-cross them the other way, and catch the object under the arm on the same side of the pattern and with the same hand that dropped it.
See also[]
3 ball under the arm throws | 3 ball under the arm catches |