Notations:
L = X for 360 and Square for PS3
M = Y for 360 and Triangle for PS3
H = A for 360 and X for PS3
P = B for 360 and Circle for PS3
~ = Cancel
f = Toward
b = Back
d = Down
u = Up
jb = Jumping Backwards
jf = Jumping Forwards
j = Jumping Straight Up
Combos are numbered and lettered--just numbers are non-meter, if it has a letter afterwards, it's a metered version of the combo.
Overhead Starter vs Crouching Opponent:
1) fH, jfH, LMH, bMH (8 Hits 37%) *You can add 3 hits and 2% damage (39%) by having 3 batarangs on hand and releasing them during the final string of bMH
1a) jfM, LLM~ES Grappling Hook, fH, jfH, LMH, bMH (13 Hits 43%) *Same note as above (45%)
2) jfM, MMH, bH, LMH, bMH (11 Hits 36%) *(38%)
2a) jfM, MMH, bH, MM~ES Grappling Hook, jfM, LMH, bMH (15 Hits 39%) *(41%)
I'll just keep updating this post as I make more.