JPL Shooting Stats & More after Gameweek 5

As we head into the 6th weekend of the Jupiler Pro League, I take a look into some basic statistics and infer how well the teams have been playing.

Shot Matrices

Dominance

Firstly, I look at the JPL team's "shot-dominance" – all credit due to Ben @experimental361 for this concept – by comparing the shots a team takes and faces, per game. 

• Standard has overall "shot supremacy" in the JPL so far: far outshooting their opponents and facing the lowest number of shots per game.   
• OHL’s defence has been the busiest, Standard’s the least busy. 
• Genk & Zulte both outshot by their opponents. Genk has the more over-worked defence of the 2, but Zulte is hovering close to the overworked territory. Both teams have top-6 aspirations – both need to limit their opponent’s more, it would appear, in their bid to do so.

Efficiency

"Shooting efficiency" (again, hat-tip Ben) is defined by the number of shots taken to score one goal. The rule-of-thumb being: 'the fewer the number of shots a team must take to score 1 goal, the higher their level of shooting efficiency, or, the better they are in front-of goal'.

• Ostende – the league leaders – have been clinical in front of goal needing roughly 6 shots to score 1 goal, which when they take over 13 shots per game, on average, implies a high return. 
• But it is Waasland Beveren, the second-highest goal scorers in the JPL, that are the most efficient at turning their shots into goals, despite taking a below-average number of shots per game.
• At the other end of the spectrum, Gent and Charleroi are so far struggling to convert theirshots into goals as well as teams further up the table are.

Defence

To assess the effectiveness of a team’s defence, we approximate by comparing the number of shots a team faces per game to the number of shots it has faced per goal conceded. Good defences limit the number of shots taken by the opposition as well as limit the number of goals they concede.

• What immediately catches your attention in the chart above is the extreme outlier: Gent. The Buffaloes have by far the most effective defence at dealing with shots in the JPL. They limit their opponents to about 10 shots per game (only Lokeren and Standard face fewer), and have conceded a goal only every 25 shots from their opponents’. 
• Standard face the lowest number of shots per game but have the third leakiest defence in the JPL. 
• Anderlecht’s defence also strays into ‘leaky’ territory despite facing the fourth lowest number of shots per game in the JPL. 
• At the opposite end of the x-axis OHL’s defensive frailties are fully exposed by this chart: they are overworked and leak goals.

Possession Game

I compare a team’s average possession statistic to their shots on target ratio (SoTR), which measures one team’s share of the sum of their & their opponent’s shots on target.

• The chart generally shows that the teams higher up the league have higher possession statistics as well as higher SoTR values. The exceptions are STVV and Zulte, which both have SoTRs than 0.5, but tend to have less possession of the ball in their games.
• Standard has the highest SoTR in the League at 0.66, translating to: 66% of the total shots on target in their games, eg if there are 15 shots on target in a game, Standard had 10, their opponent had 5. 

What's Luck Got To Do (got to do) With it?

Who need's luck when skill has spoken? Asides from just typing the worst pun on Tina Turner's classic in history, I try to assess the 'luck' JPL teams have had thus far. To do so, I turn to the PDO (credit due to James Grayson) vs. SoTR, or the 'good/lucky', matrix. PDO is the sum of shots percentage – which is the percentage of shots on targets that are converted to goals – and the save percentage – which is the percentage of an opponents’ shots on targets that are not converted to goals. PDO measures luck, averaging to 1000.

• STVV and Ostende are riding high on luck so far, with PDO values in excess of 1100, which is down to both teams scoring a high number of goals from a relatively low number of shots (than compared to, say, Anderlecht, Club Brugge & Standard, and to a lesser extent, Gent & Charleroi).
• Gent’s above average PDO is more down to their high save percentage & the stellar performances of Matz Sels. 
• Standard look to be due for a change in their fortunes some point soon. Whether or not that will come Sunday afternoon when they visit Club Brugge in what looks to be the most exciting fixture of the JPL so far this season, will be fascinating to see. 

Thanks for reading, I appreciate any feedback on how to improve. Cheers, Charlie.

Lowzer's Low Country Revue: Skill or Luck in the Belgian Jupiler Pro League at its halfway point...

The JPL has 16 teams. After 15 league matches the league is roughly at its "half-way" point. After 30 matches (ie after each team has played all other 15 teams home and away) the league then breaks into to playoff mini-leagues (Wikipedia has a good explanation). So, I thought looking at the JPL at its halfway point would be a good point to start my analysis of Belgians top-tier football division...

Skill or Luck?

I used data from soccerway.com to construct PDO, a measure of luck, and shots on target ratio (SoTR), a measure of skill, for the first 15 matches. PDO is calculated as: [goals scored/shots on target] + [goals conceded/shots on target against]. SoTR is calculated as: [shots on target for/(shots on target for + shots on target against)]. The higher the PDO the luckier a team is, the higher the SoTR the more skilful the team is. (For more detailed explanations refer back here). 

As the key to the chart explains the top-6 teams after 15 games are in Green and so on. 

Observations:

1. Generally the teams have clustered quite closely in the chart according to their league position with the exception of...
2. Mechelen, a real outlier: not only did it register the highest SoTR out of all teams in the Belgian JPL but it also experience a way low PDO over the first 15 matches. Now, this could be due to crap data or it could actually be the case that they have been really, really unlucky to be behind Sporting Charleroi and Kortrijk who were ahead of them in the table. 
3. Not only were Lierse and Cercle Brugge unlucky - according to PDO figures - but they also exhibited low skill, although Westerlo had the worst SoTR in the league.

Kortrijk and Sporting Charleroi are now in the top-6 of the league, Genk and Lokeren have fallen out of the top-6. However, to test this PDO vs. SoTR "model" as something with predictive power is probably not wise, instead it is a nice catch-all for what has happened.