Ladder queue

So I'm sitting in 3rd in my ladder and I've been unable to challenge anyone for months. I try to make a habit of checking the ladders page often, but I've missed my chance again. It would be nice if challenges had queues like sieges do.

You could try bookmarking (with watch) the games which need to finish before you can challenge. At least that way you'll be told immediately when there's an opportunity.