Okay, in another thread, the advice is "Call what you see." "Your bad calls should be no-calls", "If you don't see it, don't call it."

My question is what percentage of evidence do you need to see, before you call something?

Example, I'm trail, A1 is dribbling in one place in front of me. As A1 turns away from B1 who is closing in, B2 comes around behind and pokes the ball back toward B's basket. B1 sees what's happening, jumps out, grabs the ball, and breaks down court. A2 also sees what's coming and falls into step with the breaking B1. Now I'm new lead. I fall in behind B1 and A2, to try to get an angle. Just as B1 begins the shooting motion A2 tries to slap the ball loose. What I see is A2's arm reaching across, B1's arms moving up. I can't see the ball.

So how much do I need to see, to call this a foul? If I SEE contact between A2's arms and say B1's elbow, obviously I call it. But what if B1's outside arm is higher, A2's arm is clearly across B1's whole body, and so one would naturally extrapolate contact between A2's hand and B1's outer arm. Is that enough "seeing", or do I need to see the actual contact?

What if A2's arm is closer to B1's wrists, but the actual point of possible contact is screened by B1's body?

I can think of a lot of examples like this where I can "see" that there is probably a foul, and I can "see" that there's not much way there isn't a foul, but I didn't see the actual contact. Or I didn't see very much contact, although there would appear to have been a lot more than what I saw.

Give me some advice here. Thanks.

You just have to use common sense :)

These are the situations that i'd have to see before i can comment on them.

If you don't see actual contact, you should not make the call. In the play you described you got beat back, so you never got an angle to see through the play. I've seen enough plays where it looked like there was no way that it won't be a foul,but guess what it was not.

I've seen players clap there hands on a shot to distract the shooter, sure sounds like a foul if you are in a stack.
Jordan used to slap his own arm on layups when he turned away from the basket, and he was not doing it to soften his shot. I've seen players kick out then fall on 3 pointers. It may look like a duck, it may sound like a duck, but that don't make it a duck.

I agree - if you don't see it you can't call it. As a player I have had many situations when the ref has called a foul without actually seeing it - and has got it wrong.

Personally I think it is better to miss a call, and then respond with "I just didn't see it" than to make a call on circumstantial evidence.

Good question rainmaker. If you have a "C" then the C will have the angle. In two person, you may not have help. So, What happened to the ball. If the ball goes oob, I have a no call since I didn't see it. If the ball goes straight down I have a no call, because the Defender probablly got mostly ball. If the ball goes up, then the defender got the player across the arm. i.e. A1 starts her motion for a shot, the arms are coming upward with the ball. What do you think will happen with the ball if B1 slaps across the arms. The arms or one arm goes down and the ball continues up. Beep foul on B1.

Agreed. You must see the play.

However, in football, we're told to make, for example, PI calls based on unnatural movement. You see it in the NFL all the time. WR goes up to catch a pass. DB has his right arm around the R's waist, the the R turns, mid-air, away from the ball (towards his right) as the ball approaches from the left. Flag comes out.

Could you do this in basketball? I think you could. I can't think of an example right now though.

I've used this one: two players in the air and they crash while airborne. One has the ball. The defender lands further ahead of where he jumped from. When you jump, it basically is in a parabola. While facing midcourt, you jump and your feet leave the floor at the foul line, and you land 1 foot closer to the 3-point line, you either did not jump straight up, or you were contacted from behind. If you were not contacted from behind, you must have not jumped straight up. If the shooter was disadvantaged, then logically you have a foul, even though you did not see the contact. I've explained this one to players and they've always fessed up.