Moneypuck has us at 8.5% to win the series, pretty sure it was 8.4% yesterday, does Woll being announced as the starter swing the odds a bit according to their model? Or perhaps it has something to do with Holl?
2% according to history sure, but most of those are probably a really good team playing a really bad team. There's a ton of parity in the league in the cap era but back in the day, there were a lot more mismatches and a lot more sweeps. I wonder what the numbers are for when the team that was favored going in is down 3-0, I can guarantee you that it's better than 2%, make that a LOT better.
I can see 8.5% like moneypuck says being in the ballpark. If we assume each game is a tossup, the odds of winning 4 in a row are 6.25. Going in the Leafs were considered to be the better team so 8.5% makes some sense. Having said that, it's hard to think of the Leafs as the better team after the way they just gave it to them in game 3 but still, if someone offered me 25-1, I'd take it instantly despite how disgusted I am with this team ATM.
BTW, you're way off as far as what the betting sites are offering. Prop bets like this are always huge ripoffs, and I do mean always. Your post made me curious so I checked one site - bet365 will pay you not +2500 but +600.