Mark Langdon: Don't be sucked in by home and away form

Statistics are like a mirror – they reflect what you want to see but not always the whole picture – and those who like to use convoluted justification for football results or predictions are as bad as anyone when it comes to twisting data just enough to make their argument appear plausible.

I would be guilty as charged on more than one occasion of doing just that, so perhaps only those who are without sin should cast the first stone in preaching to fellow football punters, but perhaps it should be: let those who admit their flaws offer the first hand. Or something like that.

The misuse of expected-goals data is thankfully one area where I have rarely strayed, but it does hurt my ears or eyes if I read or listen to pundits using xG in tiny sample sizes to make some kind of grand overview of perceived success or failure.

Even the word form is rarely used correctly. The online definition says for form "the state of a sports player or team with regard to their current standard of play," which is different from the question of whether a team has won three matches in a row. Standards and results in the short term do not always equate to the same thing in a low-scoring sport such as football, even if over time, there is much more chance of the two coming together.

That's why jumping to conclusions after one game is often a quick way to the poor house.

Most people prepared to take the time to take in the Racing Post's extensive betting coverage are probably less likely to make that mistake and each individual will have their own formula for finding winners. However, one aspect of football betting that in my opinion many people overrate (including some of my colleagues!) is the difference between home and away abilities.

There will be instances where some teams are much stronger at home than the average side. Those could be geographical where altitude or extreme long distances can play a significant part, particularly in South American leagues and MLS, or even lower down the British pyramid it could be that draining coach trips and lack of funds for overnight stays impact teams scattered around in outposts. 

Playing surfaces could also definitely play a part, and artificial surfaces remain an advantage even if they are no longer like the old plastic pitches of yesteryear, while some fans can generate a hostile environment that can be worth something. Would you rather play Russell Martin's Southampton on a sunny day at St Mary's or visit Tony Pulis's Stoke with the wind swirling?

However, most teams will conform to their norm.

Brentford don't have anything unique about where they play but the Bees were being described as home specialists this season following a flying start at the Gtech Stadium. Seven wins in eight sounds impressive – it is impressive – but the schedule played a massive part with games against Crystal Palace, Southampton, Wolves, Ipswich, Bournemouth, Leicester and Newcastle (before the Toon had turned into peak Arrigo Sacchi's Milan).

Since then, Brentford have taken one point from three games against Nottingham Forest, Arsenal and Manchester City and they were knocked out of the FA Cup by Plymouth. Are Brentford really home specialists or were they just good at taking advantage of a relatively soft schedule?

You'd hear pundits be absolutely bamboozled by the difference in Brentford's home and away output, but the fixtures definitely played a part. They have lost at Liverpool, City, Tottenham, Manchester United, Fulham, Aston Villa and Chelsea, drawn at Everton and Brighton and then hammered Southampton 5-0 on their last away day.

Looking at those results, what makes Brentford terrible travellers? 

They are still to play five of the bottom seven away and the chances are Thomas Frank's team will soon start picking up more away results, while continuing to flatten out at home. Punters should always be wary of extreme outcomes. They rarely last.