Wednesday, December 14, 2011

Success in the Premier League: An Innovative Visualization

Here's an amazing interactive data visualization from Andy Kriebel's beautiful VizWiz blog. Click on the graph to go to the real thing. Enjoy!

Wednesday, December 7, 2011

The Virtue of Doing Nothing, Or: Why Martin O'Neill Doesn't Need A Transfer Budget (Quite Yet)

Amidst all the hoopla and hilarity of the season's first managerial sacking in the Premiership - Steve Bruce by Sunderland FC - it's easy to lose sight of the fact that it typically doesn't help to sack the manager. To be sure: there often seems to be a bounce-back in results for teams that appoint a new manager; but statistically speaking, the bounce-back is likely to occur in any case, with or without sacking the gaffer.

But never mind the statistical evidence. Sunderland, like the many football clubs before them, do seem to go about hiring and firing without worrying too much about what the numbers actually tell them. To be fair: aside from success on the pitch, there can be good reasons to terminate the manager. As the Guardian's Barney Ronay points out, it's often good politics and a way to manage supporters' discontent. The manager is a well paid patsy, and owners and boards need the buffer of a manager to protect themselves from criticism by the fans and media while being seen as "doing something" to improve a football club's fortunes. Or football clubs may see something in the coach that's just not working (and about which we, as outside observers, may have no information) and that needs fixing. Or, despite goodwill on all sides, the football club may in fact have enough data to make the judgment that it is time to panic - as Sunderland have evidently done.

All well and good.

But the interesting question is not "Why do they fire the manager?" Instead it is this: "What should a football club do next?" Or more specifically, what should Sunderland, this year's case in point, do next, now that they have appointed Martin O'Neill?

My advice would be this: do nothing. You heard me right. No transfers in the January window; no expensive short-term fixes (aside from the  £6 million you are shelling out for O'Neill); no need to hire lots of additional coaching staff or paint the canteen a nice shade of red and white. At this point, all the doing that needs done by the owner is done. Simply let Martin O'Neill get on with the job and see what happens.

Sunderland fans may disagree. Clearly, the team is not performing, so surely it needs to be fixed by buying in a few new faces in January. And, as you might expect, there is in fact talk of a £15-20 mio transfer budget owner Ellis Short has allegedly promised O'Neill. How can you not see the logic in that?

There are two main reasons I think the smart thing Ellis Short can do at this point is to do nothing.

Friday, December 2, 2011

Points and Relegation: The Premier League Since 1995/96

Hard to believe, but roughly one third of this year's Premier League season has been played already, and some clubs are starting to look over their shoulder with a nagging worry. They're looking at their current squad and manager, and they wonder: is it enough? Will we make it?

Sunderland's Steve Bruce is this year's first managerial sacking, surely brought on by a lack of results, but also a niggling fear of not surviving in the Premiership. As of right now, Sunderland's situation is not a full-blown emergency - but it's getting there, with 11 points from 13 matches. Things are most acute for Bolton, Wigan, and Blackburn who have managed to generate a paltry 9, 9, and 7 points, respectively, this year. 

We know they're not on target to survive the season - but how far from safety are they? To answer that question, let's look at some historical data for the last 16 seasons. Here are two key indicators of what it takes to survive: first, what was the minimum number of points that kept clubs in the league each year? And second, the maximum number of points of relegated teams - how much was not quite enough?

As the graph shows, the number of points needed to remain in the Premier League varies considerably over the years. On average, teams that managed to avoid relegation (who placed 17 in the league) managed to produce 38.6 points. But there have been seasons (2004/05) when 34 points were enough, as well as seasons (2002/03) when teams needed 44 to play another season of Premiership football.

Looked at from the perspective of the bottom teams, what was the number of points that weren't quite enough to stay in the league? As the second graph reveals, in some years (notably, 02/03, but also 96/97 and 97/98) even 40 points were insufficient for avoiding relegation. On average over the last 16 seasons, 36 points did not quite cut it.

So back to Steve Bruce's former employers at Sunderland. Their 11 points so far put them on pace to produce 32.4 points. At that rate, given the numbers above, it's no surprise that Ellis Short pulled the plug on Bruce's tenure there. There's not a single club that has survived in the league with such a low number of points. And Bolton, Wigan, and Blackburn are currently on pace to produce 26.5 (Bolton and Wigan) and 20.5 points (in the case of Blackburn). Unless something happens - and of course, it always can in football - they'll be playing in the Championship next year.

Thursday, December 1, 2011

Top 20 Premier League Teams of the Decade - Goal Differential

To satisfy the curiosity of some inquiring minds, here are the Top 20 best Premier League teams when it comes to goal difference per match. Unsurprisingly, Chelsea's 09/10 squad tops the list, in large part because of their amazing offensive output that year. And if you count carefully, you'll see that it's actually 21 teams because several were tied (e.g., Liverpool and Chelsea in 07/08). Enjoy!