It's important to note that one of the ways a catcher's CS% works is that it prevents the other team from even attempting a steal in the first place. I don't know exactly how it works, but Sparky clearly takes into account the catcher's arm rating when deciding whether or not to send the runner. So when you look at your stats at the end of the season, these "super A+" arm guys often don't throw out a lot of runners, because very few SBs are attempted against them. I use 64 Roseboro a lot, and while he does throw out a high percentage of runners attempting to steal, his real value is preventing the SB attempt in the first place.