As I've mentioned, I've been playing a ridiculous amount of Marvel Puzzle Quest. Basically, I've been trying to collect high-rarity heroes for playing.
And I've mostly been doing that in the PvE (Player vs Environment) competitive matches. In those, you can get a couple of two-star hero covers and one three-star for reaching point thresholds over the span of the whole competition. You can also get up to three covers of a three-star hero for your placement in your group of 1000.
I haven't been tracking it closely, but I play two games, and have generally been getting top-100 finishes with both games. In one of the games, I've gotten a number of top-50 as well, one or two top-20s, and a top-10.
I'm starting to find it harder, rather than easier, to get those finishes, however, despite leveling my heroes up when I can. I'm not sure what's driving that; it might be the way the system does divisions into echelons of one thousand.
One thing that has worked well is that the levels haven't (mostly) gotten a lot more difficult. So I think the difficulty scaling is done by what your highest-level character is. Mine is, and has been, almost since the start, seventy-four, and I'm deliberately not increasing that. The last several weeks has seen me pushing up the levels of my characters to get to about 70. My plan is to get my most-played ten or fifteen all to that level, then save up 150k Iso-8 (or thereabouts) and bump at least four of them up to the two-star max of 94.
I imagine I'll probably stay at that level for a while as well, getting the rest of the good characters up to that range. After that, who knows? I'm already projecting further ahead than I should.
I'll get a good comparison of whether that strategy is a good one tomorrow, though. A friend of mine, who's around the same level as me, got frustrated and bumped his two-star Thor up to 90th level (way ahead of the rest of his heroes). The difficulty scaling didn't kick in immediately, but he still hasn't finished the most recent competition (he finishes tonight; I finished this morning with placings of 90 and 101). If it kicks in tonight, with the next competition, I'll know that's how they're doing it. If not, I'll have to re-evaluate my own strategy.