I would think staffing levels in a base has more to do with it. Yes, you will generally have more nights back in base than if you were a lineholder flying 4 day trips. As to which nights those are no one knows but if you live in base it can be nice spending more time at home. If there is a TON of open time on a regular basis every month, don't plan on not working and don't plan on being home every night on reserve.

However, alternatively I've found myself covering a lot of day trips due to 30 in 7 issues. Those were nice as they were usually an out-and-backs: fly a leg, then deadhead back.

I'd say at the average regional, 50% of your trips assigned on reserve involve an overnight, the other 50% you're spending the night in base.

If your airline doesn't have staffing issues (I don't know of any that do really) then you could really luck out and never fly! (If you're the most senior reserve in base)

Oh and if you want to increase your chances of being home at night, an AM reserve shift helps....a little.