Practice against a lv 3 CPU meta knight (set to stop) on FD. You can chaingrab Meta Knight pretty easily, as he will react exactly like a Fox who is at a much higher %. I believe you can chain MK until 48 or 56% (I still have to do more testing). Anything after that, it might be possible for your opponent to act before your re-grab if they DI behind or Up (not away, that works for much longer). The timing to re-grab MK might seem a bit odd, but you'll figure it out. Once you know the timing needed on Pit's standing grab with no DI, react to the direction MK goes if he DI's your throw (The CPU should try and DI away on the 2nd chainthrow if he's on the left side of FD and you grab him from behind, facing right). Learn to react, I cannot stress it enough. Once you've outgrown the CPU left on stand, you can set him to jump or attack (your pick) and practice with that for like 10 min. Then get a friend to help you. Tell your friend which way to DI so you know before hand which way he's going to go, and after that, tell your friend to change his DI everytime, but without telling you. Once you can chaingrab MK on FD, go against a CPU Fox. He's going to be MUCH faster initially, but with you can slow down your regrabs was his % gets higher (around 48% and upwards, I find it's a similar timing to re-grabing MK). Realistically speaking, you can only Chain MK on FD or Smashville, and sometimes Yoshi's Island (brawl). I'm not sure at what specific % MK is released high enough to tech on a platform on a stage like Battlefield, but from what I've tested, he can at 24% and upwards (the 3rd down throw pretty much). You should be able to continue the chaingrab on fox from 0 % to like 96% and after that, it gets really awkward. That's insane, but remember that in a real world setting, you're not getting 12 re-grabs in a row. MK like I said earlier is from 0% to something like 56%. With platforms, MK goes from 0-24% and Fox goes from 0-56% (sometimes on PS1 or Yoshi's Story, he can escape as early as 32%). I still have to test Falco and Wolf, but Falco shouldn't be too different from Fox. U-throw can chain them at real early % but you must do a turn around grab. And anytime I mentioned you re-grab with Pit, you should ALWAYS have enough time to JC grab. ALWAYS. These percentage ranges were given because Pit's D-Throw does 8% and there is no percent scaling in training mode.
TL;DR: practice on a cpu MK on FD. if you miss the re-grab once, please read my actual post for help =]
