I have never really thought about the scap when it comes to pitching, there are too many other things to get 'right'. The other day I was warming up with one of my pitchers. We start with 15-20 overhand throws then switch to some easy sling shots followed by some easy walk-in ball circles. Then we switch to 'do what I do', where I will alternate in no particular order between OH, SS, and ball circle, the idea being to transfer some of the OH motion whip to her pitching motion. As we're doing this I realize that I have some scap retraction in OH but not in the other two. So I start to experiment with loading the scap in the underhand motions and it feels useful, especially if I add a little tilt to the throwing arm side. Now I'm wondering if I have been missing something. One thing I noticed, if I do retract the scap it allows me to swim the glove a little more. I sometimes see a high level pitcher with more glove swim than I would like but it doesn't seem to affect them negatively, now I'll have to look and see if I can detect some scap retraction in their motion.