We’ve vaulted into August and well past the 100-game mark of the 2015 MLB season. So you’d think the playoff picture would be coming into focus.

And it is—sort of.

Four of the six first-place teams hold division leads of three games or fewer entering play Sunday. And the wild-card races in both leagues are clear as pine tar, with a crowded field of viable contenders jockeying for position.

So it’s too early to crown any winners. In many cases, it’s hard to even pick a favorite.

At the very least, though, we can identify the storylines and X-factors that will help determine who will emerge from this tangled postseason scramble.

Obviously we can’t cover every angle for every team in every race. But here’s a handful of key narrative threads—significant injuries, slumping sluggers, twists of the schedule and more—that will loom large as October approaches.

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