Got a tricky one (maybe) for the mathematizers. Barstool sports runs a promo (Mortal Lock) where they give a 3-leg NFL parlay pick at pretty favorable odds (+1268 on Barstool and DK has it for +889). The promo requires a $25 bet and will return $10 in bonus cash for every leg that hits if the parlay loses. Assume that $10 can be converted to cash at 100% (because it can). Any way to figure the EV on this one? I usually hedge with a worst-case scenario of losing all three legs by making an opposite 3 leg parlay that would cover the $25 if that happened. Usually, I lose both. But the Mortal Lock will hit every so often, of course. Odds for the individual 3 legs are -154, -115, and +100. Hopefully, this is super easy and I just look mathematically incompetent . Thanks.