It's befuddling to everyone from casual fans to coaches.
Veteran referee Joe DeRosa retired from the NBA and tells Vindy.com's Greg Gulas that reffing some college games has reminded him that the block/charge call is not the same everywhere.
“The biggest rule adjustment for me has been the block-charge,” DeRosa said. “In the NBA, the defender must be in position before the shooter starts his upward shooting motion.
“In college, the defender can get there before the player actually leaves the floor and I have had to catch myself before I actually make the call,” he said.
A couple of years ago, , the NBA's director of officiating programs and development Joe Borgia explained a bit more on TrueHoop:
A lot of calls that look like charges are correctly called blocks. When you rewind these plays on your Tivo, don't do what referees make fun of fans for doing: Trying to decide if the defender's feet were set before the contact.
That's not the standard.
What you want to know is: Is the defensive player's torso set in position before the offensive player begins his upward motion?
The defense can not slide into position after the offensive player has reached this stage.
Why did they set that standard at the moment of starting upward motion? Borgia says "because we had to set it somewhere." He adds that "the moment of alighting is too late."
In years of watching film, however, Borgia has confidence they chose the correct moment.
The NBA's video rulebook has video examples galore, and explains: "To get into a legal position, the defender needs to establish himself in the path of the offensive player before contact is made, and before he starts his upward shooting motion."