10% refund question

[Fraubump]

This problem is a tricky one. "Bet it all at once and it's +ev" was the first thing that occurred to me too. Ok, say you bet $100 and lose. If you really think the proposition is +ev, nothing has changed. You still have exactly the same proposition. Why not make another bet if that proposition was +ev. The fact that you have already done it once cannot matter to whether doing it now makes sense. So, while I can't quite wrap my brain around it, I'm in the -ev camp on this one.

Let's imagine that the rebate on losses is 90%. This suddenly seems like a fantastic deal. Is it? I can easily imagine people bankrupting themselves trying martingales on this.

Anyway, I'm curious to see the definitive math on this.

One other consideration here is that Total Bet has a monthy casino bonus: I forget what the wagering req is, but if nothing else, this deal should increase the ev of clearing that bonus.