I have a problem with the idea that brush is necessary for control. Baseball pitchers don't brush. If there is brush where is the contact sensed, in the arm or the body? Some pitchers (Cat O.) where a neoprene sleeve on the elbow, in theory this would reduce the sensitivity to contact and leave the pitcher prone to wildness. Pitchers, as players, often wear sliding shorts, something else that would reduce sensitivity and cause wildness. To me brush is a sign of good mechanics but not a factor in the timing of the release.As I understand it, the primary reason for brush (of the forearm a few inches below the bend) is a reference point for accuracy. Anchoring to the same spot every time. not a collision so much as an actual brush-by, allowing a consistent location and trigger to release the ball. The wrist/hand do the work of moving the ball while coordinating with the eyes on where to locate the ball. 1 degree of change in hand (or anywhere else) position equates to 7-ish inches by the time the ball crosses the plate. You need a consistent arm reference point to allow the the wrist/hand/eye to do what they do without outside influence.