21. You call fouls to make a game fair and safe, don't just call fouls.
22. Never guess what may have happened.
23. Concentrate on each play - just one at-a-time. Down, distance, clock and team. The whole game will take care of itself.
24. Talking will get you in trouble.
25. When you see pass interference, don't let crowd noise help you call it.
26. If you're in doubt, the passer's arm was going forward and it is an incomplete pass rather than a fumble.
27. Be consistent in declaring the ball dead.
28. Concentrate your efforts on the point of attack, not away from the ball.
29. If in doubt, the block is legal rather than below the waist.
30. If it involves the safety of a player, call it.