Vs CPU, there is a YouTube video. It basically says hold down on r2 after the pitcher looks at you, the load in by L2, I recommend pushing stick towards base and L2, seems to be slightly better jump, the take your 1 step lead, all while holding R2. If you go for a second step the cpu will throw over, even if you are holding down r2. On 20 the cpu would give you 2 steps. After your one step let off r2 the pitcher will throw. Now if you are predictable the cpu will slid step or pitch out, so better to go when you got a 2 ball count. I also start tapping L1 after I let off R2 hoping that helps get the player going, but I still get bad jumps.
I have like 60SBs with Silver Barry Larkin and I am on like week 3 of owning the game. He only has 70 something stealing. And low 90 speed where I have him at Parallel IV.