Compiling Match Odds (Part IV)

Yawn!

I'm starting to get a bit bored of this series now - as I'm sure you are, so this may well be my last post on this well-trodden subject.

In case you hadn't worked it out for yourself, the last post on match odds - which in my humble opinion is the most worthwhile entry amongst the four that I've now posted - can also be used for generating match odds on any other rating mechanism you may employ that also arrives at an abstract number, rather than a percentage probability. Namely, these would be Game Form, Score Ability, Power Ratings and Penetration Plus. These are probably the most well-known, but if you're not familiar with them, then may I suggest you hunt out Paul Steele's most excellent book on ratings.

Okay, today we'll have a look at a quick and dirty method for acquiring the match odds. Once again, I have to point out that there is nothing new here. Everything that I am writing is stolen from other sources over the course of time. I should also point out that I use some of the methods I've outlined (and am about to outline) and some I don't.

Quick Match Odds (QMO)
This method is very well-known, but it doesn't have an official name (that I'm aware of), so we'll just call it Quick Match Odds. This is a nice, snappy name which I intend to copyright and use to make my millions.

I suppose giving this method a cool name also lends it a small degree of credibility - but whether it actually deserves any credibility will be up to you to decide. What I will say is that this method is probably best suited to, erm, the rather lazy amongst you.

Right, let's look at last season's match when the Arse were playing Citeh. The given odds on Betfair were:

At the time, Arsenal had played played at home on 15 occasions, and they had won 11, managed two draws  and lost two. Man City had played away 15 times, and they had won 7, drawn four and lost four. If we use this simple formula:

Home Win Odds = ((Arse home_wins + Citeh away_losses) X 100) 
                 / (total_games)

Then we get Arsenal = ((11 + 4) X 100) / (30) = 50%

A 50% chance of winning equates to match odds of 2.00 (no overround applied).

Let's do the same with Man City using the inverse formula:

Away Win Odds = ((Citeh away_wins + Arse home_losses) X 100) 
                 / (total_games)

So for Man City = (( 7 + 2) X 100) / (30) = 30%

Giving a 30% chance of winning, which equates to match odds of 3.33 (again, no overround). If we use the remaining part of the book for the draw, this gives us:

Arsenal  = 2.00
Man City = 3.33
Draw     = 5.00

As you can see, this is a rather coarse, high granularity method for deriving the match odds, but as a quick rough-and-ready guide it may have some merit. Then again, it may not.

In the words of the Blind Date voice-over guy, "You decide!"