If you're in a bid status that gives out a lot of premium, the reserve game is to put yourself on the PR list the day prior to when you start your stretch of reserve days. Especially on a WB, that PR trip will almost always make you unable to fly the final two days of your reserve availability. So you'll end up flying three or four three-day trips for the month, all for premium on top of guarantee. Obviously you'll need to be in base, but that's how these cats are pulling down 150 hour months without breaking much of a sweat.