I always thought the key for off-spin bowling is for the arm to be quite quick and for the ball to almost "pop" out with lots of revs to create drift and dip but to actaully be slower than the arm. 50 Mph is fine and not hard to achieve. Giving the ball a big rip is what you should be concentrating on in my view.
Exactly.
What happens when you try and bowl faster, Mussaduq? Do you lose control? Unless your arms are the size of bat handles you really don't need to be working out to bowl 50 mph. Not that I'm telling you to stop. Working out will take your game to the next level in many different ways. But as far bowling spin is concerned its all about rhythm. When my rhythm is (No Swearing Please) I end up bowl up crappy full tosses and quick short darts that don't do a whole lot. But when I'm in good rhythm, I'm whipping my arm across my body and focussing solely on WORKING those fingers. Like Buzz said, the ball comes out a whole lot slower than my arm speed, it's got a great loop to it and rips off the pitch. Think of it as a symphony between your arm, wrist and fingers. The problem with quick arm speed is it vastly reduces the time frame within which your fingers need to impart the spin. The best advice I can give is to keep an old ball handy and keep spinning it up into the air a lot. Like, a whole lot. Your fingers need to get stronger, faster and more nimble. Finger strengthing and mobility work might help as well but I'm no expert on that.
I'm trying to improve my pivoting when I practice these days. Someone pointed to me that I barely pivot, almost as an afterthought. But whenever I do pivot it royally (No Swearing Please) up my bowling.