[CecilOne]

I copied this from a past post by WMB on the NFHS forum:

"You’ve seen the direction the NFHS has been heading the past few years with respect to contact between a fielder and runner. For the most part, they have taken away incidental contact (train wreck) and are forcing you to call either interference or obstruction.

There are, however a couple areas where you still can call incidental contact. One occurs when a defender has the ball and steps into the runner or in front of the runner. You have contact either as the result of a tag play, or the runner had no opportunity to avoid the contact. If the defender loses the ball you probably have Safe; if they hang on you probably have an Out. But you do not have Obs or Int.

The other incident occurs within the first step or two by a RH batter going to 1B and a catcher going for the bunt. If you have contact you may judge interference, or may judge obstruction, but you can also have a no call (incidental contact). From the NFHS SB Committee: “ It’s a fair statement to make that the play situation involving a catcher moving to field a bunt in front of the plate while the BR vacates and heads toward first has always been given wider latitude regarding obstruction/interference.”

Also see pg 46 in your 2006/07 Umpires manual."