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Old 07-03-2007, 11:54 AM   #5 (permalink)
Ganchrow
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Quote:
Originally Posted by rjp View Post
I've been playing around with the Kelly calculator for simultaneous wagers, but I can't seem to figure out how it's calculating expected growth.

Based on what this article presents (along with a basic understanding of the geometric mean) I've been trying to calculate the expected growth of 2 simultaneous wagers.

Assume a quarter Kelly stake on 2 wagers at +100 odds with a 55% chance of winning. The calculator says to bet 2.4450% on each, and the expected growth is 0.4397%.

When I try to calculate the expected growth by hand:

1.048899^0.3025 x 1.00^0.4950 x (1-0.048899)^0.2025 - 1

I obtain 0.4299% (I know the middle piece isn't necessary, I just included it for clarity).

I assume I'm messing up somewhere, so any thoughts would be great!
You've neglected the 0.0629% stake on the 2-team parlay at +300. This makes the complete EV equation:

(1.048899 + 0.000629*3)^0.3025 x (1.00 - 0.000629) ^0.4950 x (1-0.048899-0.000629)^0.2025 - 1
0.4397%

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