An Introduction To Framing Your Own Football Odds
How can you frame your own football betting odds? Today on the blog Mark Taylor begins a series looking at what's involved in setting odds for a range of football betting markets.
Ten games into the current Premiership season and Manchester’s City and United find themselves separated by a mere two points as they continue their newfound rivalry of equals. It is no surprise to see the two clubs so evenly matched, but what may be slightly unexpected are their current league positions. Manchester City are presently fifth, three places above their nearest geographical opponents.
Much has been written around both the likely causes and the depth, both real and imaginary, of each side’s unexpectedly poor start to the campaign. Whilst new appointments at the very top may create temporary uncertainty and unevenness of performance, as new tactical approaches and alternative managerial styles take time to bed in, it is also true that uncharacteristically poor performances from the best aren’t quite as uncommon as people might think over relatively short batches of games.
Every couple of seasons, one of the Premiership’s best sides go winless for half a dozen matches and a sport as short of game defining goals as football often needs an entire season of matches for the best to fully assert their superiority. United have far from impressed under Moyes, but a difficult opening set of fixtures, combined with a small batch of games where random variation can show itself to good effect shouldn’t be disregarded when judging league outcomes that are only settled in May.
Early Season Considerations
Eighth position is the intersecting point in the table where seasonal goal difference usually turns negative, and whilst Liverpool and Spurs have ultimately languished there in the recent past, it is the more likely resting place for overachieving mid table sides, such as WBA, Reading, Portsmouth and Fulham than former, recent Champions.
A shake up of the old, established order may be good for the Premiership as a whole, but the most likely scenario is that the current respective positions for the Manchester rivals is more a passing point on the way up, rather than a resting place before a general descent. And this reality based, objective view is readily evident in the match prices available about the red and blue half of the city of Manchester during their brief trip to less familiar areas of the table.
Mid to lower half United were strong home favourites to dispose of a highflying Southampton side in October, despite their relative positions and with the benefit of hindsight a combination of luck (the woodwork) and cautious management (a different managerial approach)in the final quarter may have contributed to turning a predicted win into an unsatisfactory draw.
Likewise, City, despite a patchy start were considered just as likely to beat Norwich at home following their patchy 2013/14 start, as they had been to defeat the same side when finishing runner up in 2012/13. Failure of conviction and/or bad luck may have badly damaged the chances of both recent, former Champions to reclaim this campaign’s title, but in the eyes of the betting experts (the bookmaker kind), both teams remain amongst the very best.
Team Supremacy And Goal Totals
The easiest way to describe likely outcomes is in the terms of probabilities. Allowing for the bookmaker’s inevitable margin and any slight preference of opinion, City has about an 80% chance of winning a home match against Norwich at present. Envisaging an 80% chance isn’t intuitively very easy, especially as it can be expressed in a multitude of ways, from the traditional format of 1/4, through to decimal odds, 1.25 and even on to American style odds, -400. Not to mention Indonesian and Malay formats.
It is much easier for someone who regularly watches football to relate to the way in which spread bets are couched. Depending on your provider of choice, Manchester City’s supremacy chances of defeating Norwich were quoted a combined low of 2.0 goals and a high of 2.15. The mechanics of buying at 2.15 or selling at 2.0 doesn’t concern us here, but the salient point to take from such a spread quote is that City are expected, if the game was repeated countless times, to win, with an average winning margin of around 2 goals, or for a more exact figure, the mid-point of the spread.
Spread betting, for all its contrived market complexities and potential for unlimited up and down sides, is the only form of betting that speaks the same language as every football fan, namely goals. And in doing so, it provides every bettor who prefers the convention form of betting with a vital doorway into the ever expanding markets on tap in coupon based betting. The mid-point of a supremacy spread enables you to calculate almost every goal based bet on the market. Occasionally, atypical team traits can skew estimates slightly in their preferred direction, but league generalities predominately tend to hold sway.
To expand the knowledge we can take from the quotes of the spread firms, the larger the size of the supremacy, the greater the total number of goals, on average a game will see scored. A Manchester City hosting Norwich type match-up with supremacies of around 2, can except to average a couple of tenths over 3 total goals per renewal. A more closely anticipated match-up, such as Everton hosting Spurs on the same weekend, where supremacy for the host can be measured in tenths of a goal at most, on average would be lucky to see more than 2.5 goals.
The route from supremacy to total goals leads inexorably onto expected goals for each individual team in the game. Everton’s match supremacy of 0.1 of a goal, combined with a total goal expectation of 2.5 for the game, requires an Everton goal expectation for the match of 1.3 compared to 1.2 for their opponents, Spurs.
So from these simple beginnings we already have sufficient, ballpark information to produce the probabilities associated with correct scores via the perennially useful Poisson distribution. The initial probabilities for all the correct scores that lead to an Everton victory can be summed to produce an estimate of the coupon price for a home win. Similar calculations lead to the odds for the draw and a Spurs victory.
How goal expectancy decays with time adds a simple wrinkle that enables double result markets to be easily formed. 55% of goals are scored after halftime, a generalisation that some teams appear to deviate from, although much of the effect, as with home advantage or draw specialists, may be predominately down to random, unrepeatable fluctuations in relatively small batches of games, rather than real, repeatable traits.
Framing Football Markets
Over the next series of posts, I will try to show how with either a small amount of basic maths or through a use of graphs, we can use the spread based, intuitive footballing measure of goals to formulate your own odds and markets. Once you have a probability based opinion about match outcomes, ranging from simply who might win to the time and identity of the first team or player to score, comparison with the quoted odds and the search for a decent value bet can begin.
As the actual results this season so far of both Manchester teams demonstrates, a side can occupy eighth place but still be rated as a side capable of championship winning ability in future matches, whilst a high riding side, attracting much admiration, such as Southampton, can still be evaluated as just a good, mid-table outfit.
This season’s form seen in isolation should have made Southampton near equals on the coupons prior to their visit to United, but they were universally quoted as big outsiders, regardless of the actual result on the day. So to kick off this short series, rather than cribbing our match supremacies entirely from the spread firms, we will look at ways to frame our own. Five match form is often cited as a major component in odds setting, but the actions of the firms pricing up Southampton’s game with United, suggests that much longer timeframes are considered as well.
In the next part, we will look at various ways to create our own goal supremacy figures for the Premiership and then go on to use this number to frame any number of fixed odds markets.
Read more of Mark's work on his The Power Of Goals blog
And follow Mark of Twitter: @MarkTaylor0