Assigning Probability to Determine EV... ?

[grease lightnin]

I am still new to handicapping and I am stuck on this one. I bought Wong's book and I guess at some point I will actually read all of it, but all I've seen in there regarding assigning probability is that he comments one time saying that the probability you assign will always be somewhat overstated, and another place where he talks about assigning probability for parlays and he references totals and historical stats, but it seems to me that much more ought to be taken into consideration. I dunno...the book is dry as hell and it's probably in there but I thought it would be easier to come in here and ask you guys.

So let me cut to the chase...As far as I can see...there is no solid way to assign probability, therefore there is no way to truly determine EV. Am I wrong, and if so, can someone set me straight on this?

And another question...how many cappers here do all the math and determine EV and whatnot, and how many just wing it?

[tto827]

I agree with you, nobody, regardless of what they say, can determine a true probability. Now here is where I may be off, but I think that to the true cappers, it is about determining EV, then determining the error in that EV value, and using that to determine whether it is still a wise bet or not.

My personal "system" if we want to call it that, does not involve calculating anything. I rarely touch O/U cause those seem like a crap shoot to me. But I look for teams that are over/under valued primarily based on my own eye-tests, and then make bets accordingly. In the NFL I go about 50/50 but rarely bet heavy favorite ML, and bet some dog ML's so that equates to a slight profit. In college I have found 5-10 teams that I feel are undervalued (or overvalued) and have bet them (or against them) almost every week, and this has done me very well so far this year.

I doubt too many actually cap games, they may claim to, but it would take a lot of time to accurately cap games. That's why linemakers get paid the big bucks.

[grease lightnin]

Thanks for your reply. On one hand, you'd think there is no way to calculate a solid probability, and then on the other...I wonder if it's that some do have a solid way of figuring this and aren't saying anything because they don't want anyone else to know about it.

[tto827]

Thanks for your reply. On one hand, you'd think there is no way to calculate a solid probability, and then on the other...I wonder if it's that some do have a solid way of figuring this and aren't saying anything because they don't want anyone else to know about it.

You can calculate a solid probability, the only thing is that a -200 pick with a 65% chance of hitting is -2.5% EV, up that percent to 67% and it is +.5% EV. I don't believe anyone can calculate a formula that will have an error of less than +3%, at which case it becomes useless in most situations.

[grease lightnin]

How do you assign the 65%?

[antifoil]

you don't have to get the exact probability of an outcome only better than the book makers.

[tto827]

How do you assign the 65%?

By your capping... I just used it as an example, but the math guys would get that number (65%) from the formula they have created.