Tuesday 10 May 2016

Keeping Up With The Foxes.

The champagne bubbles have long since burst and the clackers have hopefully been dispatched to landfill after Leicester’s incredible title winning season, but the post mortem lingers on.

They returned to the Premier League last term as one of the strongest additions to the top tier and although survival was ultimately achieved with a healthy six points margin to 18th place, the route taken was far from smooth, with 20th position a regular resting spot during the season.

Nigel Pearson’s selectively biased cut-off point of seven wins from his final nine matches wasn’t the prelude to a personal title run in 2015/16. A record of four wins from the previous 29 is perhaps harder to totally erase from the debit column.

Instead, Claudio Ranieri was appointed to lead the charge to general apathy, if not mild hilarity, sometimes spilling over into hostility.

The easiest charge to lay at Ranieri’s door was his seeming inability to stick with a settled team. 

However, this particular foible was quickly laid to rest and a settled side, particularly in defence in hindsight became one of the cornerstones of Leicester’s astonishing rise from bottom to top.

And as the chart above hints at, another stage in 2015/16’s perfect storm was falling into place as Chelsea absented themselves from title contention, partly due to Mourinho drafting in numerous, increasingly mal-contented additions to the starting 11 with increasing regularity.

Leicester have become the 5,000/1 miracle and while bookmaker’s losses are often bathed in PR terms, there are credible sources that appear to verify real overall losses in the title winning market.

Not just at the initial headline price (one “lucky” punter allegedly cashed out his 50p bet on 5,000/1 Leicester for a 45p profit after one game of the season), but more damagingly at various points throughout the season.

An unfashionable team flirting with the upper reaches of the table early in a campaign is hardly news.
Even in 2015/16 Crystal Palace headed Leicester in the table after eight games. After 10 it was West Ham. And Hull and WBA to choose two equally unlikely Premier League winners have shone brief but bright in recent seasons.

But always the interlopers fail to sustain a title challenge, either through small sample size luck elevating them early beyond their talent, benign early schedules, the regular big hitters trampling them underfoot over the long term or injury and suspension exposing a lack of talent depth.

Until now.

Leicester steadily signed off on the requirements to send a lower, mid table team to the very top. The team was largely injury and suspension free. Jamie Vardy, for example took 35 games before he managed to get himself suspended. And Huth and Drinkwater followed suit when mere relegation form was needed to clinch the title.

The usual title contenders all partly prioritised elsewhere or coped poorly with the usual rigours of a Premier League season replete with European commitments.

Expected goals can usually discriminate the good sides from the mere lucky.

Title winners often have their fair share of both, but Leicester’s season can perhaps best be illustrated by this metric if based around where it had them finishing in season long simulations and how these estimations tallied with the bookmaking industry view over the ten months long season *.

Points won are forever in the record books, but remaining matches are mere probabilistic events until played. By combining the two, in this case using each team's expected goals records to date as a measure of future performance, Leicester's chances of pulling off the seemingly impossible can be charted over time.

The respective league positions of the teams throughout the season can be easily checked here.

The bookmaking odds constantly lag behind the optimism of the agnostic expected goals modelling and simulation, although prior knowledge of the usual fate of title upstarts may account for this reasonably pessimistic stance in the case of the former. No one has gate crashed the title party from outside the usual elite since 1995.

But the Foxes were increasingly taken seriously from all sides following respective wins over Chelsea, Spurs, Liverpool and Man City from week 16 onwards.  

Even when WHU briefly headed Leicester in third place after 10 matches, the Hammers didn't quite possess the underlying expected goals stats and number of earned points to muscle into the probabilistic expected goals title reckoning.

Leicester spent their title teens posting on average around 1.7 expected goals per game while conceding just over 1.3 in return. But when chance creation slipped by a couple of tenths, the defence caught the slack to maintain a healthy positive expected goals difference as they moved from their twenties into early middle age.

Lots of things fell right for Leicester during 2015/16, either at their own hand or the meltdown of other North London rivals. But they did provide a valuable lesson. 

Namely, the past, especially a cursory reading of general trends, rather than a deeper examination of expected achievements is only an imperfect indicator of the future for a reasonably young sporting ecosystem, such as the Premier League.

* many of these simulations have been posted on twitter over the season, so other than the natural variation within 10,000 sims using the same input, none have been “tweaked”.

No comments:

Post a Comment