Wednesday 25 July 2012

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!"

6 comments:

  1. Thank you!
    But what if Citeh has no away wins?

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  2. Could you write a topic about Asian Handicap?:)

    ReplyDelete
  3. If one of the teams has no away wins - or indeed if one of the teams has no home losses - then this method (which, as stated, does leave something to be desired), runs into problems. This method should only be considered a "rough and ready" approach.

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  4. Hi, I may well do a post on Asians, as I think its a neglected area.

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  5. Hi Soccer dude,
    I found a slight improvement on the quick and dirty method, which I used by picking it up from a soccerwidow video.
    Its pretty simple and requires just previous game data, rather than gointo to many details, I am posting an example of what I worked out on tonights everton and wba game.


    Everton V WBA statistical analysis and odds


    Last 30 home premier league games Everton record. And odds based on that.

    Everton won 15/30 = odds of 2
    draw 8/30 = odds of 3.75
    away 7/30 = odds of 4.29


    Last 30 away fixtures WBA and odds based on that

    Home team won 13/30 = odds of 2.31
    Draw 7/30 = odds of 4.29
    WBA won 10/30 = odds of 3


    Odds based on average of both teams respective home , away performance.
    Everton home win odds= 15/30 + 13/30 = odds of 2.14
    Draw odds= 8/30 + 7/30 = odds of 4
    WBA odds = 7/30 + 10/30 = odds of 3.53

    Odds based on last 10yrs head to head minimum with atleast 6 home fixtures for a team

    starting from 02/03 season in 6 Everton home fixtures v WBA Premier league

    Everton won 4/6 = odds of 1.5
    Draw 1/6 = odds of 6
    WBA 1/6 = odds of 6

    odds based on average of home and away performance of Everton, WBA respectively and head to head record at Everton.

    Everton win odds
    Average of odds 2.14 and 1.5, worked out by converting to percentage first.
    ie (1/2.14 * 100 + 1/1.5 * 100) / 2 = 56.7 % in odds = 1.76

    Draw odds
    (1/4*100 + 1/6*100)/2 = 20.83 % in odds = 4.8

    WBA odds = (1/3.53 * 100 + 1/6 * 100)/2 = 22.5 % = odds of 4.44

    So final price based on past performance and head to head stats for Everton V WBA as follows.

    Everton = 1.76
    Draw = 4.8
    WBA = 4.44

    Current betfair market
    everton 1.58
    draw 4.4
    wba 6.8

    (using the same model, I came up with arsenal being a shade under even money against liverpool at home tonight)

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  6. Could you please point us towards how to include defensive strength into calculations, looked all over and cant find help

    ReplyDelete

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