I'm glad that you're planning on doing this.
Are you going to be looking up 2012 pitch speeds on any other pitch f/x site or are you just going to enter the speeds by taking a certain amount off of each pitch that you already have documented.
Either way, have you determined how much you're going to subtract from each pitch type?
I can't remember exactly how it worked on MLB 11 when it comes to certain pitches, but I'm pretty sure that I remember that changeups needed to remain the same. Fastballs needed about 1.3-2.3 mph subtracted (depending on the speed and the type of fastball). Sliders needed 1.7-2.3 mph subtracted. I never figured out curveballs, but I think I went with subtracting 1.1-1.3 mph. I think I used the same for slurves.
With that said, the softer a pitcher threw their fastball, the more he seemed to need subtracted off of it. For example, guys who had 90 mph fastballs in game seemed to be able to throw 93-94 fairly often and players who averaged 95 seemed to hardly ever throw 97. I ended up subtracting about 1.9-2.3 (depending on the pitcher) mph off of players who averaged 87-93 mph with their fastball and only about 1.7 mph off of players who averaged in the 94-95 range.
On top of that, each type of fastball seemed to a little different than the other when it came to this. It seemed like 4 seam fastballs usually needed 1.9-2.3 mph subtracted from their average speed. Sinkers and 2 seam fastballs seemed to need less subtracted.
It's been a while since I edited the speeds, so these numbers might not be exactly the way that it was, but it sounds right to me.
I definitely wouldn't base any of your edits off of what I just typed. I just wanted to explain what I was asking.
The whole in game system is silly and needs to be revamped.