Pulled foot mechanic and timing

[GarthB]

you arent required to appeal check swings. if you as a plate umpire feel that it is questionable you can ask for help, but it is certainly not required.

OBR 9.02 (c) comment, second paragraph:

"Appeals on a half swing may be made only on the call of a ball and when asked to appeal, the home plate umpire MUST refer to a base umpire for his judgment on the halfswing."