When Is It Incidental?

[cmcramer]

Player A streaks down court, looking back for a long pass from his teammate. Player B defends by standing stationary, still as a statue, 10 feet in front of A's path. Players collide in an awful crash

1) with no player possessing the ball - it's still in flight
2) with A just catching the pass and turning his head to face forward
3) with Player B just catching the pass - while holding his position on the floor - just before A arrives.

What's the call? When is this type of contact 'incidental' ?

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