Is over-reliance on a certain player a good or bad thing?

A look at what the stats say. Who is getting all the goals and assists for each team? Is balance good or bad?

First up, a bit of a philosophical update. When I launched this substack, I decided to avoid getting into data and analytics. That was driven by a couple of things. Partly it was a function of what I’d been reading, and trying to get back in touch with the ‘romantic’ side of the game, that comes from looking at it with your eyes and interpreting it with your heart more than your mind. And it was partly because there is a load of analytical stuff out there already which is very good. And I figured I had nothing extra to say.

But recently, I read a couple of books on analytics and I decided I’d dip my toe in the water. And I got sucked in. So here we are. I’ve been absent from substack for a few weeks (I’m sure nobody noticed!), exploring and (re)teaching myself to code.

Maybe it’s a mid-life crisis. I’m okay with that.

Anyway, I bring you my first article featuring data. It won’t be the last, sorry! I decided to do something that attempts to answer the question of how reliant various teams are on certain players (or not), and what that means. Away we go…

Goals and assists have undergone a (very minor) evolution in recent times. Mainstream media has been kind enough to do some addition for us, to present us with ‘Goal Contributions’. This is sold to us as the primary indicator of a player’s worth/ability.

It’s nice that assists have risen to prominence, but we still only have the tip of the iceberg. I’ll address that in another post, but for now, let’s have a look at goals and assists and understand how they are spread across the twenty Premier League clubs.

I’m going to twist it slightly, and use expected goals and expected assists. Goals are pretty streaky, where luck plays a big factor in how well a striker performs over a small sample size of shots. There’s some form in there too, of course, but xG is a better indicator of performance. The same goes for assists. The volume of assists doesn’t necessarily indicate the quality of chances a player is creating. It only tells us how many have been converted. So expected assists (or xA) is a better measure.

I’ve plotted what proportion of xG and xA each player has contributed to their team’s overall total to understand the key men for club. Not only that, but in what way are they contributing. I then pushed them into five groups, and there were a couple of teams that had a distinct pattern.

I’ve defined the groups as follows:

Star Man - A stand-out individual delivering high numbers of xG and xA, with relatively little support from the rest of the team.

Healthy Spread - Self-explanatory; contributions coming from across the team, with nobody dominating.

Duo - Two stand-out individuals, one creating, one getting into goal-scoring positions. Relatively little support from the rest. May well work as a key partnership.

Defined Roles - Contributions from across the team, but a clear division between creating and scoring.

Target Man - Clear gap between striker and the rest of the team for xG. Creative burden falls on rest of the team.

Healthy Spread

Bournemouth, Crystal Palace, Newcastle, West Ham, Fulham, Arsenal

For each of the plots, I’ve labelled the top five contributors. Generally, the top five gives us an idea of how a team performs at the business end of the pitch.

Let’s start with Bournemouth, who have a nice, balanced shape to their contributions. Semenyo is clearly the star man, leading the way for expected goals and assists. But most of Bournemouth’s leading men are clustered along the x=y line, so the burden of creativity and finishing is shared.

Crystal Palace have a bit of a split between xG and xA, but it’s not that clearly defined; the goalscorers are still creating, and vice versa. What is interesting about Palace is that their expected assists come primarily from their wing backs; a clear tactical plan.

Newcastle have a similar shape to Bournemouth, with Isak, Gordon and Barnes leading the way. But they are ably supported by Joelinton and Lewis Hall.

West Ham look a little different. They have a range of players getting goalscoring chances in the form of Kudus, Soucek, Antonio, Paqueta and Bowen, but they are heavily reliant on Bowen when it comes to creating chances; he accounts for around 30% of their xA.

Another team who can get goals from everywhere are Fulham. But we can see Alex Iwobi is picking up the bulk of the creative burden.

Finally we have Arsenal, who only just fit into this category, I would say. Kai Haverttz and Bukayo Saka are doing the bulk of the work, but there is backup in the form of Martinelli, Trossard, and Decland Rice. I suspect they are missing Odegaard!

Defined Roles

Ipswich, Tottenham

In this style, we see a defined split in responsibilities between goalscoring and creation, with relatively little in between.

First up are Ispwich, where almost 50% of their chances fall to Szmodics and Delap, with the creativity largely coming from Leif Davis.

Spurs are even more defined, with Solanke and Brennan Johnson charged with getting on the end of things, and Kulusevski and Son creating chances. James Maddison is kind of in the middle. But there is a big gap between that top five and the rest of the team. As an aside, I’m writing this as I watch Spurs dismantle City, and this may look different in an hour!

That brings us to the end of the more balanced teams. I suppose the implication is that these teams are sharing the load of creating and scoring goals, and are perhaps more resilient to individuals getting injured or losing form. More on that later. For now, we move onto…

Line Leaders

Man City, Nottingham Forest, Southampton, Aston Villa

The thing I love about this cluster of teams is that they are so different. Different ends of the table, different styles of play, different types of forwards.

It might be easy to assume that Man City are nicely balanced. I probably thought so before I looked at this. In fact, they are perhaps the least balanced team in the Premier League. Erling Haaland account for a staggering 50% of their xG. Assists come from all over the place, but a notable mention for Savinho in his debut season. I find this interesting because when defending a team, you look to stop the guy on the end of things and/or you stop the supply. But Haaland is such a phenomenon that stopping him is easier said than done. And stopping the supply is like playing whack-a-mole.

Let’s look at the other team with a big man up front. Nottingham Forest have won lots of admirers this season, and we can see Chris Wood is the man they look to supply. He’s scored plenty of goals, but this shows he’s getting the chances too, and he’s not just in a freak purple patch. Whether he can keep it up for a full season is another matter, but he certainly hard to stop, and maybe Forest haven’t been found out yet.

Next we have Southampton, a team down at the bottom but they like to knock the ball about. Despite that, Cameron Archer is the focal point of this team. I find it both fascinating and ironic that they have a similar distribution to City.

Then we have Aston Villa, who look to Watkins to put the ball in the net. He’s had a patchy start to the season, but the chances are coming his way. Jhon Duran provides backup from the bench, with the supply coming from Rogers, Digne, and Tielemans.

The Star Man

Liverpool, Chelsea, Wolves

Fans of these clubs probably could’ve guessed who the star men were before seeing this chart.

Let’s start with leaders Liverpool. Wow, look at Mo Salah, probably the leader for the player of the year at this point. Liverpool are probably more balanced this year in their style of play, but the reliance on Salah is plain to see, with nobody else in the squad anywhere close. Diaz has knocked a few goals in, but he’s seriously over-performing on goals against his xG. Will Liverpool falter if Mo Salah drops off? Or can someone else step up?

Cole Palmer is once again the main man for Chelsea, though I should note that Nicolas Jackson is getting plenty of chances. But Palmer is clearly the lynchpin.

For Wolves we can see a similar shape, with Matteus Cunha doing his best to keep the ship afloat. Strand Larsen seems to be the main beneficiary of that, but with Wolves, it’s perhaps a little easier for the opposition to focus on stopping Cunha. And stop him, you stop Wolves.

The Duo

Leicester, Everton, Brighton

With these clubs, we can see two players really dominating proceedings. Let’s start with Leicester, where Buonanotte is creating the chances, and Jamie Vardy is charged with finishing them off. This isn’t too far off a ‘Line Leader’ shape, and it’s probably only because Buonanotte is getting a few chances himself that I resisted pushing Leicester into that category.

Everton are the most defined here. Calvert-Lewin is the guy getting the chances, but Dwight McNeil is having an excellent season in the number 10 role. It’s a new partnership, but it’s performing well. The concern for Everton might be that the rest aren’t contributing much.

Then we have Brighton. Brighton are one of those teams that seem well-balanced, but Mitoma is the guy unlocking defences, with Welbeck finishing things off. There’s a bit of support from the likes of Rutter and Minteh, but there’s a clear double act making things happen for Brighton.

We finish with a couple of teams that didn’t fit into any of the above categories. First up are Brentford who have a very defined trio of players making things happen.

Mbuemo is having a fine season, then we have Damsgaard creating plenty of chances, and Wissa getting into goalscoring positions. Stopping all three of them feels like a challenge!

Then we have United, who are very difficult to pin down. Of course, it’s been a difficult season for United so far, so some of their distribution surprised me.

We can see Bruno Fernandes is the star man, but he’s not totally dominating. Garnacho and Zirkzee are getting plenty of chances, and Casemiro and Rashford are doing okay with creating. It will be interesting to see if and how this changes under the new manager.

In Conclusion

Before I looked at this, I surmised that it would be preferable to have a healthy spread of goals and assists coming from around the team. I probably still think that, but it’s interesting to note that none of the teams featured here are having a great season. Indeed, many of them are under-performing. Defence plays a part in that of course, and I’ve ignored it here.

On the flip-side, it’s the unbalanced teams that are doing well. Is the reality, then, that Salah’s form has played a big part in Liverpool sitting at the top of the league? Is the City/Forest model of having a focal point and a range of supply lines the way to go? Or maybe Brighton’s model of primary creator/goalscorer has some merit?

Is this analysis telling us that where teams have a healthy spread, it’s because one or two of their difference-makers have fallen back into the pack? This analysis only spans 11 games, so form can make a big difference. It’ll be interesting to revisit this at the end of the season.

I want to finish by talking about assists. I have a problem with assists. An assist with a high xA rating doesn’t always (or often) come with a high difficulty rating, and for me, isn’t a true measure of creativity. The only mitigation is that, similar to the player converting a tap-in, you’ve got to be in the right position to do it. But in a future post, I’ll look at the overlap between assists and other creative indicators.

TME