Legal Guarding Position

[RefBob]

Thanks for the replies. I imagine the issue is figuring out what is exactly moving into the path of an airborne opponent. It seems pretty tough that A1 goes full speed for a layup, checks before he goes airborne that no B players are in front of him, lands with one (or two) feet and then because of his momentum immediately contacts B1 who established a court spot while A1 was airborne right in front of where he knew A1 was going to land and contact him - and then A1 gets called for a foul. A1 never would have had a chance to see B1.