Who's winning the Golden Boot? A statistical approach.
Nobody would have expected Aubameyang flop out of leading scorer group this season, while DCL and Son top the chart along side with Salah.
DCL, Son, Salah scored 11 goals so far. In this in-depth I am going to analyse these three players statistically.
Goal Scoring Table
| Rank | Name | Team | Goal |
|---|---|---|---|
| 1 | Dominic Calvert-Lewin | Everton | 11 |
| 1 | Mohamed Salah | Liverpool | 11 |
| 1 | Son Heung-Min | Tottenham | 11 |
| 4 | Jamie Vardy | Leicester City | 10 |
| 5 | Patrick Bamford | Leeds United | 9 |
| 5 | Harry Kane | Tottenham | 9 |
xG Trend in Golden Boot
| Season | Golden Boot | Goals | xG |
|---|---|---|---|
| 17/18 | Mohamed Salah | 32 | 22.2 |
| 18/19 | Mohamed Salah / Sadio Mane / Aubameyang | 22 | 19 / 16.1 / 20.7 |
| 19/20 | Jamie Vardy | 23 | 20.3 |
xG is the mean value of expected performance.
See the gap between xG and Goals in 17/18 season, Salah's expected performance was 22 goals yet he outscored his expected performance. And again each and every Golden Boot winner and contenders out-performed their expected goals. Thus following presumption:
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higher the xG higher the probability to score goals.
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gap between xG and goals should be adjusted with other metrics.
Hence I've selected these 8 metrics to explain the gap between xG and goals:
G/SoT, SoT%, SoT/90, Att_Pen, Dist, Targ_90, np:G-xG, npxG/Sh
Supplementary Metrics
G/SoT
Goal/Shot on Target
SoT%
Shot of Target Percentile
SoT/90
Shot on Target/90
Att_Pen
Touches in Attacking Penalty Area
Dist
Average distance from the goal from all shots taken.
Targ_90
Passes aimed at the player tried.
np:G-xG
non-penalty Goals - xG
npxG/Sh
non-penalty Goals/Shots
Above metrics can be categorized into two groups.
Finishing Indicator(FI): G/SoT, SoT%, np:G-xG, npxG/Sh
Environmental Indicator(EI): SoT/90, Att_Pen, Dist, Targ_90
DCL, Salah, Son Statistical Comparison
xG Comparison
| Name | xG | G-xG |
|---|---|---|
| Dominic Calvert-Lewin | 8.1 | 2.9 |
| Mohamed Salah | 7.8 | 3.2 |
| Son Heung-Min | 4.5 | 6.5 |
DCL has the highest xG of 8.1. Son's G-xG is 6.5 and is beyond comparison with other two. To explain this huge gap we should look into Finishing Indicator and Environmental Indicator.
Finishing Indicator
| Name | G/SoT | SoT% | np:G-xG | npxG/Sh |
|---|---|---|---|---|
| Dominic Calvert-Lewin | 0.48 | 59 | 2.9 | 0.21 |
| Mohamed Salah | 0.33 | 46.2 | 2 | 0.10 |
| Son Heung-Min | 0.79 | 60.9 | 6.5 | 0.19 |
As you can see in this radar chart, Son is exceptional at finishing. Son's G-xG can be explained with his finishing skill this season.Also Son's np:G-xG has been rising since his debut in London.
| Season | np:G-xG |
|---|---|
| 17/18 | +1.9 |
| 18/19 | +4.2 |
| 19/20 | +3.0 |
| 20/21 | +6.5 |
Little flop in 19/20 can be excused Spurs were having set-back season from the UCL Final defeat. Also note that Son played at wing-back for handful of games under Mourinho in 19/20. His “over-performance” might not drop this season.
Salah's finishing is not so high compared to DCL and Son. He scored 5 goals through Penalty Kick. Little surprising that Salah's finishing wasn't as lethal as I thought.
Environmental Indicator
| Name | SoT/90 | Att_Pen | Dist | Targ_90 |
|---|---|---|---|---|
| Dominic Calvert-Lewin | 1.8 | 73 | 11.3 | 48.9 |
| Mohamed Salah | 1.55 | 98 | 17.2 | 63.79 |
| Son Heung-Min | 1.17 | 44 | 15.3 | 46.91 |
However, Salah has the most goal-friendly environment among three. DCL's environment is quite favorable to him too. We can presume that Salah's goal scoring environment is boosted by the team performance. Liverpool is the most attacking team in the league right now.
DCL's EI is very optimal for centre-forward. His touches in attacking penalty area is behind Salah, but this indicates that DCL doesn't engage at build up play more than he should. While Salah is hugely influencial to Liverpool's play making. DCL's sole mission is to shoot and score goal. DCL's Shot on Target number is the highest here.
Summary
Only DCL plays at central position, and this grants him higher xG. While Son's finishing skill is another level this season. And Salah has been okay, but he is on pen so this is huge advantage at Golden Boot race.
My guess is Salah would take the throne again, with DCL and Son scoring more than 20 goals each.
p.s.
I'll update the post if ohter contenders climb up. Omission of Vardy in this article lingers in my mind.