Stripes - no doubt some guys will just post quotes from the rulebook, but we all really know that getting this call right involves much more than just what's on a printed page.
Although this is usually quoted by many as being the toughest call, I really no longer have any problem with it. I guess it's because over the years, I have seen a bazillion of these and I got to the point years ago where the collision either "looks like a charge" or "looks like a block" to me. I suppose it just becomes instinctive after so many of them, and I'm sure it will get that way for you, too.
Here are some "words of wisdom" gleaned from various camps I have attended on this point:
1) did the defender "beat him to the spot" - if not, call the block (actually, this is a pretty good test and easy to comprehend)
2) call the block if any of the following happened at the point of contact and you won't get any "flak":
a) the defender had an arm or leg sticking out
b) the defender was moving - regardless of whether or not his movement was still legal - that's too hard for anyone to comprehend (OK, I didn't say I agree with these, only that I was told them)
c) you are in doubt - you'll be right 95% of the time anyway
3) call the charge if the ball handler had his head or shoulder down and/or initiated the contact
4) call the charge if the offensive coach is a real howler monkey, just to hear him howl so you can T his butt
OK, I made the last one up, but it's good advice anyway.
