[jerod6694]

I am trying to figure out how to determine the win probability when you have 2 different spreads for the purpose of using Kelly to get my wager amount. For example, we'll say Pinnacle has +3 -105/-105 and I am able to bet the same game at +5 -110/-110. Trying to figure the win probability of my bet in comparison to the Pinnacle line has me stuck.

I believe may I know some of the steps but I know I am missing some too.

Any help would be greatly appreciated

Thanks

[FourLengthsClear]

I am assuming that +3 is a fair line and represents a 50% win probability.

To calculate the win probability of a bet on +5, you need the push probabilities for +3, +4 and +5. On the basis that this is a CBB bet, these figures would be in the region of:

+3 - 4.6%
+4 - 4.0%
+5 - 4.0%

On the basis of +3 being the fair line, we can map the game as follows:

Fav loses or wins by 1 or 2 - 47.7% (50% minus half of the push probability of +3)
Fav wins by 3 - 4.6%
Fav wins by 4 -4.0%
Fav wins by 5 - 4.0%
Fav wins by 6 or more - 39.7%

In terms of your bet (+5), this means

Win - 56.3%
Push - 4.0%
Loss - 39.7%

In terms of getting the push probability data you need, the half point calculator has some but you would be well advised not to rely on these (I believe they are quite old) and to gather the data to be able to compile your own.

[jerod6694]

How did you come up with the exact probabilities? And how do you go about figuring in the -110 vig of the +5 into the overall win probability?

This is probably simpler than I am making it but I am just a little confused.

Thanks for your help.

[FourLengthsClear]

How did you come up with the exact probabilities? And how do you go about figuring in the -110 vig of the +5 into the overall win probability?

This is probably simpler than I am making it but I am just a little confused.

Thanks for your help.

The push probabilities I have used are from my own database.

The -110 is not a factor in calculating the win probability. It would, of course, be used to calculate your edge/EV as follows:

Win probability
divided by
implied probability of the odds you bet at

minus 1

i.e

56.3% multiplied by (100.0 divided by 96.0) = 58.65% (This prorates the +5 push probability)
divided by
110/210 = 52.38%
=
1.1196

minus 1

+EV is therefore 11.96%