Yeah, I noticed that too.....
Hardest thing for me though?
...*thinking, thinking, thinking, gets it!* I got it! When the elite 4 uses a full restore or something like that, your attack does a little bit less or a little bit more than it was before. Like if the pokemon had 15 hp left, then the next time you used a super powerful attack to bring it down that much would make it either like 18hp or 13 hp. Just some examples.