Pitcher tossing ball
 

This is from a Facebook Umpire forum.
HS Varsity Fed rules. R1 on 1st base. Pitcher engages rubber and begins to toss the ball with his bare hand and catch it repeatedly.
There are many guys saying this is not a balk!!!
I found 6-1-3 f casebook. Any others?

How many others do you need?

It's a balk in all codes.

Bob. I had to un follow the group. It was me and 2 guys arguing with a dozen guys saying we're making up rules.

What if he is getting comfortable on the rubber?

Not talking adjusting the ball. F1 is taking the sign and tossing the ball and catching it.

No one does it "repeatedly" (as in the OP) as part of getting comfortable on the rubber.

Now if he has the ball in his bare hand and all in one motion -- puts the pivot foot on the rubber, steps forward with the free foot, tosses the ball into the glove, leans in for the sign -- then, sure, I pass.

I don't have that play in mind when reading the OP.

You're picturing how they are posting, Bob. Pitcher just nervously tossing the ball while engaged. I can't believe the group had HS Umpires saying it's nothing.