There is only one story at the moment – the continuing controversy of Rafa Benitez at Chelsea. Yet despite the fans unrelenting abuse of the interim manager, an analysis of the teams performance shows that Chelsea are in fact performing slightly better under the new man than under Di Matteo.
I started thinking of doing this analysis before Rafa’s blew up at Middlesbrough. And, obviously, the media frenzy that followed forced my hand. So, I am going to compare Rafa’s performance with that of his predecessor at Chelsea, Di Matteo. And I am going to analyse only Premiership matches; the main reason is that I don’t have readily available performance data for other matches.
My comparison is over Chelsea’s first 26 Premiership matches of this season – that is before their last match away at Man City – of these, 12 were played under Di Matteo and the last 14 under Benitez. And, I’ll be using the only three metrics I have: Points gained, Shots, and Shots on target.
For the analysis I am using a method called Decision tree, which is probably the best to compare statistically the performance of two individuals, and also rather easy to read and understand by all. These performances are also compared using three ’conditional ‘ parameters: Home/Away, Wins/Draws/Losses, and opposition team ranking : top, middle, bottom.
The results shows that there are some differences, some small, some large, in the three performance parameters examine. We can see that there has been a slight improvement in performance under Benitez with regards to Shots (16.07 vs. 13.83) and Shots on target (9.50 vs. 8.00), but Di Matteo has a slight Points advantage. However, none of these differences is statistically significant! Overall, the performance of the two managers has been pretty much the same.
The only significant difference to come out of my analysis is between Home and Away shots (17.15 vs. 12.92), but probably Chelsea’s fans had already spotted this one. Anyway, see the results below.
Venue: Home vs. Away
Opposition team rank: top, mid, bottom
So with little to split the two managers, maybe the fan’s ire should be directed more towards the director’s box than the dugout. What Benitez has said in the past may have upset the fans, but when it comes to what happens on the pitch, there is little to choose between him and the venerated Di Matteo.