Sunday, September 11, 2005
Simple Bubble Maths
I found myself on hovering around the bubble this evening on BoDog, in their $100 tournament. 65 runners were left, 63 paid, I had 6000 chips (about 1% of the total in play) with blinds 400-800. 63rd paid $250, but here's the punchline, so did 62nd-46th. And 45th-37th only $350, 36th-28th $450. Even I could see that there was some value in waiting out the next two places. But how much ?
Suppose I was confronted with a chance to double up. What would be the EV of doubling my chips ? Assuming that, if I pass or win I'm guaranteed $250. If I pass and make the money, everyone's got $250, which takes $15K off the prize pool ($100K guarantee). My 1% of the chips is worth $250 + $85K * 0.01 = $1100 in total. By a similar calculation, 2% of the chips at this point would be worth $1950.
So, to make my double-or-nothing play, I would need a 56.4% chance of winning (1100/1950) to make it profitable. While we never have an exact double-or-nothing scenario, this indicates how much extra edge we need compared to normal - 56% compared to 50%. So what I did in the event was I think correct - I passed one marginal situation that I would normally move in with, but when I found A8 in the small blind with the big blind having a similar stack to me, I felt that was good enough and moved in. To my horror he called me - to my relief he also had A8. Two players duly busted, I made my move and ran into AK to record an unusual (for me) bubble minus one finish for $250. For all my maths, the key hands were when I had QQ and AA on the big blind and was walked each time. How annoying is that ?!
Anyway, we see that even in this case, where almost everyone would clam up, you only need a bit more of an edge to make your move. Do not fear the bubble. Embrace it ! For it is your friend !
Suppose I was confronted with a chance to double up. What would be the EV of doubling my chips ? Assuming that, if I pass or win I'm guaranteed $250. If I pass and make the money, everyone's got $250, which takes $15K off the prize pool ($100K guarantee). My 1% of the chips is worth $250 + $85K * 0.01 = $1100 in total. By a similar calculation, 2% of the chips at this point would be worth $1950.
So, to make my double-or-nothing play, I would need a 56.4% chance of winning (1100/1950) to make it profitable. While we never have an exact double-or-nothing scenario, this indicates how much extra edge we need compared to normal - 56% compared to 50%. So what I did in the event was I think correct - I passed one marginal situation that I would normally move in with, but when I found A8 in the small blind with the big blind having a similar stack to me, I felt that was good enough and moved in. To my horror he called me - to my relief he also had A8. Two players duly busted, I made my move and ran into AK to record an unusual (for me) bubble minus one finish for $250. For all my maths, the key hands were when I had QQ and AA on the big blind and was walked each time. How annoying is that ?!
Anyway, we see that even in this case, where almost everyone would clam up, you only need a bit more of an edge to make your move. Do not fear the bubble. Embrace it ! For it is your friend !
# posted by Andy_Ward @ 11:15 PM 
