Sportpunter

Models…..What are they and what are they good for?

No I’m not talking about the model that you see in the picture, that’s just merely an opportunity to include her. No, I’m talking about statistical models. What are they?

Well according to Wikipedia, a statistical model is

“a set of mathematical equations which describe the behaviour of an object of study in terms of random variables and their associated probability distributions”

For those who have no idea what on earth that means, let me explain. In the sports gambling world, a statistical model is a model which analyses past data and tries to predict future outcomes. It assumes that patterns found in the past will occur again in the future. And I’m not just talking about patterns like how some teams have it up on other teams, I’m talking about long term patterns.

You see when a lot of people bet, they look for patterns as well, and as such make bets that are justified in their mind, but unjustified statistically. For example, a punter may decide to bet on Newcastle in the soccer, because they claim that they never lose three in a row. Or perhaps they’ve won their last three against their opposition. Or perhaps the oppositions form without their main striker is terrible, and he’s currently out with injury.

These are all patterns. And almost all punters bet using these. Some are justified, others are not. There are plenty of professional punters out there that make a stack betting on patterns like this, but there are 100 times more people that do not.

All of the options above to bet on Newcastle are not justified, and whilst they might have well happened in the past, this is not a key to suggesting that they will happen in the future. Punters, will generally find patterns in any kind of randomness.

As a simple test, below we have 2 graphs. One of them has been derived by random numbers and is purely random, the other is not. Can you guess which graph is purely random, the first graph or the second?

Basically this outlines one of the key notions in statistical analysis. It is very easy, especially for an untrained eye to find patterns in randomness. When we look at the first graph we see patterns, we see little stretches of cluttered dots, some areas where no dots actually appear. If we look hard enough, we can come to some conclusions about what is happening in this graph. If we look at the second graph, we see not a lot of clusters. The dots are very evenly spread and not many big gaps.

An untrained eye would immediately say that the second graph is random, when in fact the opposite is true. The first graph is random. Even in randomness patterns occur. So we need to work out what patterns are random, and what patterns can give us a betting edge.

So how is a model different? Sportpunter’s models analyse past data in order to come to conclusions about the future. It not only finds patterns, but it determines if these patterns are merely by chance or if a real trend occurs.

It’s very hard for our simple brains to wade through thousands of pieces of data in order to not only find a pattern, but also determine its significance, if at all.

That’s where computers come in. And in the next series on modelling, not only will we find ourselves with another excuse for another picture of a model, but we will also talk about how Sportpunter uses the computer to write models.

And the butterfly model? Oh, I photographed her whilst holidaying in Paris. Nice place Paris.

Along with out normal Soccer model, we also predict odds for the premiership as well as finishing dead last.

Here are the probabilities and associated bets for the premiership after lasts round for several of the leagues

Australian A Leauge

So we have decent overlays on Brisbane, Central Coast and Perth for the outsider. More open market than most leagues, generally because of the finals system.

Spain

Barcelona look the good bet here, with a nice 22.9% overlay for them to win the season over Real Madrid.

Italy

Good money again on the favourite, with a reasonable outsider in Sampdoria. An overlay exists on Udinese, but at odds of $201, don’t get your hopes up.

English Premier League

Last year we had big overlays on Man U throughout the season at reasonable odds. This year the big overlay exists on Liverpool, who after a terrible start, seems to be back on the winning side

France

Big overlay on league leader Bordeaux. Their odds keep on shortening with every match

Germany

Early favourite Bayern Munchen has had a very indifferent start to the year, which gives us big overlays on Bayer Leverkusen and other outsiders.

Netherlands

50/50 chance by our predictions for PSV to take the top spot at the end of the year

Scotland

Always a two horse race when it comes to the Scottish Premier League. Small overlay on Celtic to take the crown.

All the free soccer predictions are available here. And be sure to check back regularly for more updates.

I hate to bang on about this in the third post, but its worth mentioning I believe. Previously I posted how I believe the grand final could well be a low scoring match as well as commenting about how there might be some value in first score being a behind so maybe I’ll back that last comment with a bit more information.

Since 2003 more goals have been kicked than behinds. In fact on average a team kicks 14.2 goals and 12.5 behinds. The quarter by quarter averages do not show up a pattern against this. The first quarter averages 3.3 goals, 2.9 behinds. The second quarter also 3.3 goals, 2.9 behind. The third quarter 3.5 goals 2.9 behinds and the last quarter is usually the highest scoring with on average 4.0 goals and 3.7 behinds.

So it makes sense that a bookie will price up the first scoring shot of a behind as less likely than a goal. But what about finals? In finals the game might well be more competitive. And whilst I haven’t done any analysis of goal and point scoring in closely rated teams, finals might well show a different pattern.

Indeed it does. In the 73 finals since 2003, the average team has scored in the first quarter 3.0 goals and 3.0 behinds. The second quarter has resulted in 2.9 goals and 2.8 behinds. The third quarter 3.4 goals 2.8 behind and the last “blow-out” quarter 4.8 goals and 2.8 behinds.

Interestingly enough, for the first quarter and almost the first half in finals, the number of behinds scored is equivalent to the number of goals. In the 2009 finals, the first quarter has resulted in on average 2.8 goals 3.5 behinds.

And with windy wet weather again being predicted, the chances of a first up behind are increased (eg. The windy game between Western Bulldogs and Brisbane resulted in 4 goals 8 kicked in the first quarter). Or even better, the wet grand final of Collingwood vs Brisbane of which one goal 8 was kicked in the first quarter.

Grand finals alone have higher scoring behinds in the first quarter than finals or any other match. Of the 7 grand finals since 2002, the average first quarter score per team is 2.9 goals, 3.3 behinds.

So there is value in the first quarter first scoring shot behind. Seems like in this instance, finals and grand finals, are a slightly different kettle of fish.

Sportpunter AFL Betting Record

What a ripper grand final it will be. That is, apart from the thunderstorms and possible hail that is meant to disrupt it.

I posted previously how, given this case, the unders might be the better bet, and indeed centrebet’s line has decreased from 170.5 down to 165.5. Maybe some of you took the advice and plundered on. However in a low scoring windy wet game there might be another market that one could use. In a wet and windy day, more behinds are usually kicked than goals, but it seems that the bookies prices for these have not yet been adjusted.

You can get odds of 3.80 for Geelong to first kick a behind and 3.90 for the saints to first kick a behind at Bet Choice and Sportsbet Oz respectively. This equates to a 51.9% chance of the first score being a behind. Whilst the saints have been pretty accurate in front of goal of late, everyone remembers the yips that have plagued Geelong of late.

Last years grand final for one, where they kicked 11 goals 23 points. But the reason why there might be an overlay here is not because of the accuracy of the players, but the likelihood that players might take a while to account for the wind, the greater chance that players will go for goal from 50 meters out only to see the wet ball drop short, and the probability that there will be several “rushed” behinds if the rain starts to pour.

It wouldn’t be much of an advantage I would think, perhaps a 55% chance of the first score behind a behind. But even with a 55% chance of a behind up front, that’s still a 5.9% overlay, and perhaps worth taking up.

The first shot on goal is always exciting anyway.

And the actual match? Well this has last year all over it, just with the teams in reverse. Last year Hawthorn finished second on the ladder, but come finals time got all their players back and thrashed the opposition in the finals matches. Sound like Geelong this year? Well last year Geelong only lost one game for the year and were the dominant team, but were a little shaky in the lead up games to the finals and even only narrowly defeated western bulldogs in the prelim. Sound like the saints this year?

You bet. The team going into this game with the most confidence would no doubt be Geelong, despite the saints being the premier side throughout the year. Either way it should be a cracker. I’m just hoping for a low scoring point kicking game. Oh, and a close one for interests sake.

Sportputer’s AFL betting history is shown here

Centrebet are the first to give out over/under odds and I like the look of the unders here. 1.90 available for under 170.5 points. Now that might sound like a small total, but both clubs have by far the best two defences in the competition. When they played in round 14, only 176 points were scored, and yet that was played in the nice indoor conditions of the docklands.

But this is outdoor, and the forecast for Saturday isn’t looking that great. According to the Australian Bureau of Meteorology, Melbourne will have this Saturday experience: “Scattered showers and the chance of thunderstorms with hail. Winds west to northwesterly averaging up to 40 km/h”

So a windy, possibly wet day, which all goes for a low scoring contest. Not only that, but Geelongs last three matches against Collingwood, Western Bulldogs and Fremantle ranked in total scores of 167, 178 and 148. Average 164. Whilst St. Kilda’s last four matches against Western Bulldogs, Collingwood, Melbourne and North Melbourne scored in total 113, 132, 181 and 123 points respectively. Average 137

Looks to me to be value. Expect the odds to come in if the weather predictions become more likely to be true.

Whilst sportpunter have not come up with any specific predictions for the Brownlow medal, one of our regular clients, Flosso has come up with his predictions which you can download in the forum. He’s done pretty good in past years, and this year he reckons Ablett will take out the crown.

Not a very adventurous prediction, but the probability that he suggests means a significant overlay. I managed to get on with odds of $3.10 at betfair, and the odds have come in a bit since.

Check out flosso’s predictions here:

http://www.sportpunter.com/forum/viewtopic.php?t=5196