Sawbones: The analogy of a wrist brace to a cast is a bit misleading. A cast is on 24x7, for weeks or months straight. A wrist brace is on occasionally for a few hours, with many taking them off between shots. The bottom line is that the two experiences are not close to being the same.
Another thing that's lost in these discussions is that wrist braces come in all shapes, sizes, and varying degrees of functionality. You can't make a blanket statement regarding what they do or don't do. Yes, some are extremely restrictive, but others allow for a remarkable amount of flexibility. For instance, a Mongoose Optimum and a Robby's Revs II are both wrist braces, but their respective functionality and restrictiveness are night and day. It all depends on what you're looking for.
I can go either way, but I use a wrist brace to be able to compete effectively in longer formats. It's one thing bowling a 3-game league set, and completely another bowling 30-40 games over a two day period.
It's really dangerous to make generalizations in this area.
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"Sometimes, the best move is the one we don't make"