Expected Points Differences: League Oneby Mike Holden / 05 October 2016, 09:42Tweet
In his second of four articles on managers' Expected Points Differences Mike Holden (@Ratings_Mike) delves into League One.
(For a full description of the Expected Points Differences concept check out the information beneath the graphic below)
Tony Mowbray fell on his sword at Coventry last week - and did so with great integrity - but this expected points comparison shows the full extent of his shortcomings at the Ricoh this season. The Sky Blues were more than seven points adrift of market expectations after ten matches, only for caretaker Mark Venus to cut that deficit with their first win next time out at Port Vale.
So there’s no obvious contender to be the next casualty in League One. Neil Harris has the worst record as it stands, but he’s a club legend and did a remarkable job to get the Lions the play-off final last season, having been only two points better off at this stage 12 months ago. So he’ll surely be given ample time to turn things around, and you’d be shocked if this form continued.
However, Russell Slade must be looking over his shoulder all of a sudden after seven matches without a win. Relegated Charlton were widely fancied to challenge for automatic promotion this term but currently sit in 18th, following Saturday’s home defeat to Rochdale. The Addicks have only won one of their six matches at the The Valley under the former Cardiff boss.
With the club’s Belgian owners likely to come increasing fire from disenfranchised supporters, chairman Roland Duchatelet might be inclined - not for the first time - to make the manager the scapegoat and lay all of the blame for that rising discontent at his doorstep. Slade needs a win, especially at home, and the next game against Coventry could be pivotal.
Micky Mellon must also be concerned. He campaigned for a bigger playing budget in the summer, suggesting he would turn Shrewsbury into the Harlem Globetrotters with a bit more backing. It might have been an off-the-cuff remark to the local newspaper but such vivid proclamations aren’t easily forgotten and Salop are now third from bottom with only two wins.
At the top end, Graham Alexander, David Flitcroft and Stuart McCall each look pretty untouchable with a bit of leverage banked for a rainy day. Given Scunthorpe’s blistering finish to last season, Alexander should be setting in his sights on the title. The Iron have picked up 45 points from the last 19 matches, which would be 109 points over the course of a 46-game season.
Meanwhile, Bruno Ribeiro has surprised at Port Vale and will almost certainly stick around beyond Christmas, which is more than many neutral observers expected when he was appointed. The Valiants are currently sixth with a long list of casualties at Vale Park - including Scunthorpe - but the complexion could soon change with away trips to MK Dons and Sheffield United next up.
Expected Points Difference - What is it?
Expected Points is a way of converting bookmakers’ match prices into predicted outcomes by turning percentage probabilities into points values. It’s a helpful method of measuring performance versus expectations because it puts a cap on how much samples of data can be skewed by outliers, such as a freak 16/1 winner that subsequently needs 16 poor results to be cancelled out.
Example: if Team A is deemed to have a 52 per cent chance of winning before a match and the draw is a 28 per cent chance, their Expected Points value is 1.84 (0.52 x 3, plus 0.28). Likewise, if Team B has a 20 per cent chance of winning, their Expected Points value is 0.88 (0.20 x 3, plus 0.28).
If the match then finishes a draw, the result is worth -0.84 points to Team A and +0.12 points to Team B. This can be an excellent way of measuring pressure on managers because bookmakers’ prices tend to be a reliable gage of what they should be achieving. Consistently, those towards the bottom of the table tend to be the ones out of a job first - or next!