There are many pitch types in MLB Power Pros and its 2008 sequel. This is a list and a brief description of each, from a right-hander perspective.
4-seam fastball-4SFB: Is the basic pitch, every pitcher AND fielder has one, can be 49-105 mph. Generally above 74 mph.
2-seam fastball-2SFB: secondary fastball pitch, only 3 levels, all others have 7 levels. A bit slower than 4SFB, but with slight downward, and Throwing Hand-side movement.
Cutter-CUT: Left-side breaking pitch, harder than a SLD, and is really called a "Cut Fastball".
Slider-SLD: Main leftside breaker, which is the slowest of the three, but with more motion and smetimes, has slight vertical break.
Hard Slider-H-SLD: A slider, but about 3 mph faster, and with a little less break.
Curveball-CB: Main leftdown breaking ball, it goes down, contrary to popular belief that it's just a breaker going the opposite way as THROWING HAND.
Slow Curve-SCB: Slower than a CB, but also a looping break. Thrown by Joba Chamberlain and Franklin Morales.
Drop Curve-DCB: AKA "12-6 curve", is a pitch with very, very slight horizontal break, and large downward break. Useful as a ground ball pitch, vs. lefties as a RHP or vs. righties as a LHP.
Slurve-SLV: Slider+Curve=Slurve. Similar to what happens when a soccer ball is headed/kicked toward a net, supposedly.
Knuckle Curve-KNCB: Knuckleball+Curve=Knuckle Curve. Unlike a KN, no random movement or slowness is active.
Knuckleball-KN: Slowest pitch in the game, with very random movement, very hard to master.
Changeup-CHG: Main downward breaker, and is probably the best groundball pitch when used properly.
Circle Changeup-CCHG: A CHG with minimal arm-side break.
Splitter-SPLT: A changeup with about 55% of the break and much harder. AKA split-finger, split-fingered fastball, etc.
Foshball-FOSH: Downward pitch. Nothing else really known, primarily used by Jeff Suppan and Tom Gordon.
Forkball-FORK: Another downward pitch, like a SPLT with about 3-5 mph slower, and more random tumbling break.
Palmball-PALM: It's name says it all- thrown by holding in the palm, don't use your fingers.
Sinker-SNK: Main right-down pitch, with slightly more downward than horizontal action.
Hard Sinker-H-SNK: A sinker with a bit of MPH added, with less action.
Screwball-SC: A reverse curveball. Hard to throw.
Shuuto-SHU: Right-side breaking pitch. Main type for this type of break.
Hard Shuuto-H-SHU: Shuuto, bit faster, less motion.
Sinking Fastball-SIFB: Harder than a Hard Shuuto, and has downward movement as well as sideways movement.