AFTER William Gallas’s threat to score an own goal and defeat the side he was playing for, he has left Chelsea to become a Labour MP.

I’ve been dying to crack that joke for almost a week, so forgive me.

Anyway, the morning after the transfer window slammed shut (one of my favourite clichés, incidentally) the newspapers were full of reports about Chelsea sealing their last-minute swoop (another favourite). Chelsea get Cole, the papers said. But I just wondered. Shouldn’t the papers have read Arsenal get Gallas?

After all, the France defence was the best in the world by the time of the World Cup and Gallas was at its heart. There is a very good case for arguing that Gallas is among the very best players in the world.

Now clearly, the Gallas-Cole swap was made necessary by the breakdown in relations between these players and their respective clubs. But this still leaves the question — who got the better deal?

Much of the press has been certain that the advantage lies with Chelsea if only because Gallas, 29, is so much older. Yet previous work by the Fink Tank suggests that while strikers peak in their mid-twenties, defenders stay on top of their game at least until their mid-thirties. There’s a great deal of juice left in Gallas. And who knows how Cole, 25, will feel about things in five years’ time? So the Fink Tank decided that a reasonable first step in analysing the deal was to look at the on-field actions of Cole and Gallas over the past season and see who added more points when compared to the average player in their position.

Dr Ian Graham, Sasha Antonyuk and Dr Henry Stott looked at every move of every Premiership player and related it to points. But it turns out that the comparison was not a simple one. Actions that directly lead to goals or directly prevent them are the most valuable to a team.

Thus strikers and centre backs generally add more points than full backs and holding midfield players. This is generally reflected in the price that clubs pay for players in the different positions. And it is reflected, too, in the Fink Tank’s valuation of Cole and Gallas.

Assuming a direct swap, Arsenal’s points total last season would have been boosted by 5.4 points by having Gallas play for them, while Chelsea would have actually lost four points replacing Gallas with Cole.

This suggests that, all other things being equal, signing Gallas was the real coup that the newspapers should have been celebrating. Yet a little more careful analysis makes things look rather different. Yes, Gallas is more valuable than Cole. Yet the man he was really replacing was not Cole at all — it was Sol Campbell. And a direct swap of a fit Gallas for a fit Campbell last season would actually have seen Arsenal achieve three fewer points. So the real transfer story of the close season was Arsenal letting Campbell go.

Now Chelsea. Cole is actually being brought in as a replacement for Asier Del Horno. Del Horno got a bad press but it is hard to see why. The Fink Tank points valuation suggests that swapping Cole for Del Horno makes no difference.

What about Wayne Bridge? When we first looked at this, Fink Tank thought that Cole was only marginally better than Bridge for Chelsea. Since then the gap has grown. José Mourinho was definitely right to prefer Cole to even a fit Bridge. It might make five or more points difference, which is a huge amount.

Anyway, at least everyone’s agents got rich.

finktank@thetimes.co.uk