>>28547379Just don't try to boost your stats before Ditto is dead, because, more often than not, Ditto will have a Choice Scarf and without boosted stats, he's pretty much useless. A scarfed Ditto also can't do anything to bulky Pokemon, and every team has one of those. T-Waving it or burning it or setting up a Sub before it comes out is also a viable option.
Ditto's main flaw is that it's predictable, it has one role in every team and that's it. Which is why if Team Preview didn't exist, Ditto would probably be OU, since if you don't know the opponent has a Ditto, you can't counter it.