Monday, 14 May 2018

Non-Shot xG Passing Stats. The Complete Picture.

The 2017/18 Premier League season is now a wrap and you’ll be bombarded with end of season advanced stats, both team based and for individuals.

Mostly, these figures will largely confirm what we intuitively know. 

Kevin De Bruyne may not have come close to Mo Salah’s goal output, both actual and expected, but he contributed massively to Manchester City’s creative avalanche with outrageous passing ability.

The gradual advent of pass based, non-shot expected goals models is beginning to highlight the contribution of those creative players who often provide the raw material for the scorers to bask in the celebratory spotlight.

However, many of these interpretations have exclusively concentrated on the positive contributions made by attempting to advance the ball, while ignoring the cost when a player’s misplaced pass leads to a turnover.

Possession comes with responsibility as well as opportunity and while a completed pass rightly causes an uptick in expected goals fortunes for a side and a player, there is always a price to pay if the ball instead ends up at the feet of the opposition.

Infogol’s non-shot passing model gives an expected goals figure to every possible possession location on the field of play, but it will be different from the perspective of the two teams.

Possession on the edge of your own box will be worth very little in terms of non-shot expected goals, but would be hugely valuable if possession switched to your opponents.

So a misplaced pass that turns over possession deep in your own half will lose your side the tiny expected goals valuation that went along with that possession, but will also hand a much larger chunk of NS xG to your rivals.

The cost of losing that possession would be significant.

Similarly, lose possession deep in your opponents half and you are conceding the hard won NS xG owned by progressing deep into opposition territory and you’ll also hand a small amount of NS xG associated with opposition possession in their own half.

Just as we can tally the positive contributions made by players, we can also see what their misplaced passes cost their side.

It is inevitable that KDB will lose possession for his side in valuable areas, it is the natural cost of the high tariff passes he often attempts, but ignoring these entries in the debit side of the creative ledger omits the realistic representation of football as experienced by those who watch the full 90 minutes rather than just the highlight reel.

To give a flavour of the much more rounded picture NS model can convey, here’s a breakdown of the percentage of team passing creativity owned by players from the 2017/18 season, but also balanced by the percentage of team NS xG lost by misplaced passes that belong to the individual.

Top 10 Defenders.

Bottom 10 Defenders

Top 10 Midfielders

Bottom 10 Midfielders

Top 10 Strikers (+ Wayne).

Bottom 10 Strikers

Here’s the top and bottom 10 list of players that compares the amount of good things their passes have contributed against the times when their passing radar has gone astray.

They’ve been sorted by position, because the opportunity to create or make mistakes is largely driven by where you play. I’ve also compared the player’s importance to his side.

For example, Aaron Cresswell’s passes has contributed 17.5% of West Ham’s total positive change in non-shot xG and he has been responsible for 10.5% of the NS xG the Hammers have lost due to misplaced passes.

At the other end of the scale, Benteke’s passes has contributed 2.7% of Palace’s positive NS xG from passing, but he’s given away 10.3% of his side’s total generosity to their opponents.

I’ve included Rooney as a striker just to give him a suitable Premier League send off.


  1. I understand why its called expected goal. But why do you call it "Non shot" ?? What does it suppose to mean?is it because its not a shot just a pass or?

  2. The name,s to distinguish an xG that is based on passes from expected goals figures that have been around for years and relate solely to the likelihood that an attempt on goal will result in a goal