pitching rule question
 

does a pitcher from the set position have to "disengage" from the rubber to throw to first / second / or third? a coach and a couple of fellow blues have told me this? I thought that as long as the pitcher steps toward the base he can remain in contact with the rubber? please help with this local disagreement.

From the set position the pitcher may step and throw to a base without disengaging from the pitcher's rubber.

FED 6-1-3

ART. 3 . . . For the set position, (clipped) During these preliminary motions and during the set position until a delivery motion occurs, the pitcher may turn on his pivot foot or lift it in a jump turn to step with the non-pivot foot toward a base while throwing or feinting as outlined in 6-2-4 and 2-28-5, ...

OBR 8.01

(c) At any time during the pitcher’s preliminary movements and until his natural pitching motion commits him to the pitch, he may throw to any base provided he steps directly toward such base before making the throw.