This is definitely a positive EV bet, right?

[IceColdAces]

I'm a huge Oakland A's fan and a buddy of mine is a huge Angels fan. He kids me all the time about how the A's choke every year down the stretch (and righfully so), but I haven't been too worried this year with their magic number down to 2. Well after the A's blow up yesterday in Seattle he accepted this bet:

If the A's don't clinch before they play the Angels for 4 games this weekend the Angles would have to win all 4 games to win the division. I laid him 10-1 odds on that happening. He actually wants to bet $500 for $5000 on this. I accepted. I know the A's are chokers, but wouldn't most of you accept this wager?

Thoughts please!