Legal screen/Incidental Contact
 

B1 guarding dribler A1 bringing ball up the floor. A2 sets screen at division line. A1 seeing screen set acclerates towards the frontcourt. B1 focused on A1 does not see A2's screen and runs him over. Shoulder of B1 hits screener A2 in the torso. B1 clearly did not see screen.

This is a HTBT type of situation and depends on many factors:

1. What has been called for rest of game.
2. Time and distance of the game.
3. Does A1 have an open lane to basket

In most situations, I am going to make incidental contact unless similar plays have been a foul earlier in game or Team A is somehow disadvantaged by the situation. HTBT

This is a HTBT moment. It would depend on how much displacement took place. There is a certain level of contact that should be expected. And screens are expected to have contact which can be sometimes violent. If there is a foul, it would be on B1, but there might not be any foul under the right circumstances.

Peace

What did B1 do after hitting A2?

(a) The screen is set directly behind B1, outside his field of vision, and within one normal step. Then, foul on A2.

(b) the screen is set to within B1's field of vision. Then foul on B1.

4-27-4 and 4-27-5 (definition of incidental contact)
ART. 4 . . . A player who is screened within his/her visual field is expected to
avoid contact with the screener by stopping or going around the screener. In
cases of screens outside the visual field, the opponent may make inadvertent
contact with the screener, and such contact is to be ruled incidental contact,
provided the screener is not displaced if he/she has the ball.
ART. 5 . . . If, however, a player approaches an opponent from behind or from
a position from which he/she has no reasonable chance to play the ball without
making contact with the opponent, the responsibility is on the player in the
unfavorable position.
4-40-3,4,5
ART. 3 . . . When screening a stationary opponent from the front or side (within
the visual field), the screener may be anywhere short of contact.
ART. 4 . . . When screening a stationary opponent from behind (outside the
visual field), the screener must allow the opponent one normal step backward
without contact.
ART. 5 . . . When screening a moving opponent, the screener must allow the
opponent time and distance to avoid contact by stopping or changing direction.
The speed of the player to be screened will determine where the screener may
take his/her stationary position. The position will vary and may be one to two
normal steps or strides from the opponent.

As always, I agree with Bob, need more info. Not saying what happened after contact leaves a big information gap.

Specifically: did B1 stop or plow through?