Graphic: staying strong

I had a nickname for Avram Grant, the former Chelsea first-team coach. I used to call him “The Null Hypothesis”. I tried to get this one going as a chant at Stamford Bridge, but I got nowhere. I think that's because the Lower West Stand isn't much for singing. I will try it again if ever I sit in the Shed End.

The thinking behind the nickname is this. Grant didn't seem to say anything. Not to the fans, not to the players. He didn't have much of a track record, either, yet he did as well, possibly better, than José Mourinho when the Fink Tank delved into his stats.

Those who believe that managers make a big difference might be presented with Grant, whose success suggests that any relationship between manager and results may be a matter of chance. He's the null hypothesis, geddit?

Well, let's say you don't and just press on, shall we?

A recent academic study by David Berri, the American economist, and a number of colleagues concurs that managers and coaches do not make much difference to sporting outcomes. Although their work did not look at soccer - it was based on following basketball players in the United States as they performed under different gaffers - I am, at the very least, inclined to believe that the football manager's role in success and failure is overstated.

Nevertheless, there are managers whose records give me pause when making that judgment. One is the brilliant Sir Alex Ferguson, a second is Arsène Wenger. Then there is Martin O'Neill.

Take a look at the graphic. Drawn up by Dr Henry Stott, Dr Ian Graham and Dr Mark Latham, it plots the strength rating of Aston Villa under O'Neill and his predecessor, David O'Leary.

The strength measure is the number of goals we would expect the team to score against an average opponent, divided by the number of goals we would expect them to concede. Obviously, the higher this number is the better, and there has been a clear and substantial rise under O'Neill.

This is not because of a rise in wages. The Fink Tank plots wages against the number of points gained and is able to estimate how many points a team might expect for the money they spent. In most seasons Villa have been where you would expect; now they are clearly above. Last season the team registered 6.8 more points than the money led one to expect. One of the biggest improvements under O'Neill has come through accuracy. Their ability to convert shots on target into goals has gone up impressively. The big jump came last season and has been maintained this season. Villa do not rate as well as most other teams in terms of creating chances but are much better at putting them away.

There have also been some smart purchases. Brad Friedel, the US player, for instance, is an excellent goalkeeper who added 6.4 points to Blackburn Rovers last season, if their performance with him is contrasted with the way they would have fared with an average goalkeeper. The retention of Gareth Barry was also every bit as important as O'Neill believed - he was Villa's best player last season.

This season Villa are 5.3 points ahead of expectations. Can they make the Champions League? Absolutely. They have a 29 per cent chance of a top-four finish and a 74 per cent chance of finishing in the top five. At the start of the season these figures were 10 per cent and 24 per cent respectively.

If Grant is “The Null Hypothesis”, is O'Neill “The Significant Other”?

Or maybe I should just give up with that joke.