Kobbie Mainoo and Statistics

Manchester United's 18 year old midfielder has very poor underlying statistics. How much does that matter?

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If you pay attention to football discourse on social media then you know international breaks are really boring. There’s not much going on so the apps all delve into the same recycled topics to try and grab engagement or just entertain you to pass along the time. It’s always the same stuff. The December 2006 Goals of the Season compilation, some rewriting history about a past great - usually Zidane, this time Thierry Henry - and, depending on how quickly they run through all the topics, we’ll sometimes get back to the stats vs the eye test thing.

It started innocently enough last Tuesday when Athletic writer Jon Mackenzie tweeted about how teams just don’t shoot from distance the way they did a decade ago.

This didn’t really set anything off until a day later when Statsbomb CEO Ted Knutson responded as to how wrong Mackenzie was.

Knutson’s Statsbomb has evolved into a company that now works with football clubs to provide them with high level data, thought Knutson has worked at multiple clubs himself. He knows what he’s talking about. This didn’t really blow up into a whole thing except that the night before Kobbie Mainoo happened.

Manchester United’s 18 year old midfielder made his full England debut and turned in a man of the match display in 72 minutes against Belgium. The performance moved him from being the future hopes of all Manchester United fans to now being the future hopes of England fans as well.

Mainoo thrust himself onto the main stage, which comes with more scrutiny. With Mainoo legitimately putting himself into the conversation for Euro 2024 more people began to take a look at him, including the numbers people. What they found was, Mainoo’s underlying numbers aren’t good. Actually, they’re quite terrible.

I didn’t see anyone specifically saying Mainoo wasn’t good. They were merely pointing out his lack of numbers is potentially not a great sign for the future. Simply pointing that out seemed to completely rattle every single Manchester United fan - especially the numbers guys.

People were shouting how the numbers lack all context, the system he plays in is terrible¹ and prevents him from having good numbers. On and on to the point that numbers people were almost saying actually you can’t look at numbers. Numbers aren’t good and don’t mean anything.

We’ve apparently lost the plot here so let’s talk about numbers again.

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Advanced stats in football exist for one single reason: trying to figure out who is good and who isn’t.

Football is pretty simple. 22 players run around for 90 minutes trying to kick a ball into a goal to score for their team. At the end of 90 minutes you count up how many goals each team has scored and whoever has more is declared the winner. When you dive deeper into it you see some individuals tend to score more than others, so you count up how many goals each player is scoring and from there you can figure out who the best one is.

For about 100 years that’s all we did.

Eventually we realized there’s 11 players on each team, but most of the goals are scored by just one or two of them. How can we figure out if the other nine players are good. At first we started looking at the guys who are able to pass the ball to the guys that score the goals. Getting the ball to the guy who’s going to score is obviously pretty important.

Soon we realized that while scoring goals is the most important part of football, there’s more to the game than that. You can’t score goals unless you shoot the ball so let’s count how many shots teams or players are taking so we know who’s most likely to score the most.

But passing the ball to the goalscorer and shooting the ball itself are still only your attacking players. That’s only going to be about four or five players on the pitch. There still something missing. You can’t shoot the ball unless you have the ball near the opponents goal. If you have a player who doesn’t score goals but moves the ball from one end of the pitch to his teammates in the attacking third that’s very valuable. Therefore we should count those things too.

No one has ever said that the numbers tell you everything or that you don’t need to actually watch the matches. The numbers can tell you the story of a match you didn’t see, but they’re not going to tell how good a specific player is. You always have to mix the two things together. No one is ever going to tell you otherwise.

Number are good because they’ll give you a starting point. They'll tell you what a player does do. They’ll tell you what a player doesn’t do. Rather than drawing conclusions from those numbers, they should be the springboard for you to ask questions. Player X does a lot of this action, how does that affect his team? Is his team gaining value from it? If they aren’t, does that mean the stat isn’t useful or is there something that the player isn’t doing? As I wrote two years ago, the most important question when looking at any stat is “what comes next?”

For example, the numbers tell us that Manchester United successfully get the ball into their box more often this season than the previous seven season except for last year. However their scoring is way down, as is their xG, and their total shots. What’s happening here?

When you look at more numbers you can find some added context here. United only take 1.56 touches in the box per box entry, one of the worst ratios in the league. They get in, but they don’t stay there. More can be learned when we see how they get in.

Alejandro Garnacho ranks in the 92nd percentile in Europe’s big five leagues in progressive carries. He ranks in the 97th percentile in carries into the box, and leads United with 4.24 successful box entries per 90. All of those things are valuable and important for a team, but as always, what comes next?

Garnacho makes just 1.65 key passes per 90, 50th percentile in Europe. His xA is just 0.1 putting him in the 11th percentile among attackers in Europe. In other words, he’s not passing inside the box much², and when he does, he’s not creating great chances. What Garancho is doing when he gets the ball into the box is shooting. He ranks in the 95th percentile with 3.25 shots per 90. Unfortunately he’s not taking good shots. He’s in the 55th percentile for xG per shot and to make matters even worse, he’s in the 9th percentile for shots on target percent, hitting the mark with just 26.8 percent of his shots.

Garnacho carries the ball forward at an extremely high level. He gets the ball into the box plenty of times per game. But when he does, he’s most likely to take a poor shot and not put it on target. Last season Jadon Sancho lead United with 4.48 successful box entries per match. United thought they replaced that this season with Garnacho but failed to account for “what comes next?”

There is truth to the sentiment that the numbers are better for measuring attacking players. Of course they are. From the earliest days of data pioneers data analysts have struggled to quantify defense. Chris Anderson and David Sally’s The Numbers Game was published in 2009 and when it came to analyzing defenders they asked “how do you quantify something that doesn’t happen?”

A defenders job is to not allow the other team to score goals. Goals in football are pretty rare. Only about three of them are scored per game, which means for roughly 89 minutes, no goals are being scored. How much of that is down to the defenders?

You can look at tackles and blocks and things like that, but those all rely on an action happening. You can only block a shot if a shot is taken. Therefore the players who will have the most blocks will likely come from the teams that concede the most shots - that doesn’t mean they’re the best defenders.

We have a similar problem when it comes to midfielders which is made all the more complicated by how many different types of midfielders have. Some play further up the pitch and score goals and get assists. Others don’t venture forward but focus on moving the ball up the pitch to their teammates. Some stay really deep to focus on defending.

How do you measure this? Simply looking at tackles or progressive passes isn’t going to do it. Some midfielders live outside of those areas. Not everyone lives within the numbers but that doesn’t mean their contributions don’t show up in the numbers. You just have to know where to look.

Midfield is the heartbeat of a team. Midfielders have the most effect of anyone since their job is to both protect the defense and get the ball to the attacking players. You want to see how a midfielders impact shows up in the numbers, look around them.

Nemanja Matic was an excellent defensive midfielder in his prime. During the 2019-20 season he was a game changer for Manchester United. You wouldn’t know that from looking at his individual numbers. He didn’t make a lot of tackles or intercept a lot of passes, but when he played not only did United tend to win, but they conceded far fewer goals and a much lower xG.

That right there is a starting point. When you have numbers like that it should trigger your brain to say “why are United so much better when Matic plays? What is Matic doing - or not doing that is having such an impact?”

From there you go to the video tape and take a look. You’ll see that Matic didn’t do a lot of running. He stayed home defensively and was a master of slowing teams down, delaying attackers just enough so his teammates could get back and make a play on the ball. He cuts off angles and forces opponents to pass the ball where he wants them to pass it, typically into an area where United are ready to defend.

When paired with Fred he provided cover for Fred to be more aggressive in trying to win the ball back. If he failed, Matic was there to delay until Fred could recover. In possession Matic’s numbers were never anything great, but he was very composed on the ball and knew how to move it quickly to players that were better than him. When he played next to Pogba he was very good at getting the ball to Pogba and getting the heck out of his way so Pogba had as much space as possible to cook. When Pogba’s numbers dropped off when playing with another midfielder partner, that was part of the reason why.

Some attackers live outside the numbers as well. They make runs that open up space for their teammates. Their gravity drags defenders closer to them so their teammates have more room. If you can’t see it in their individual numbers, look at the team’s numbers! If the team performs better when that player is on the pitch, that’s your queue to ask why that is. You dive into the video and those little things like making runs for others will quickly become apparent.

If the team performs worse when that player is on the pitch you go to the video with a different set of questions. Are those things not valuable? Is he not doing those things well? Or is he doing those things well and his teammates aren’t taking advantage of it? Perhaps his teammates are the problem, or perhaps they just don’t fit together?

That’s where Kobbie Mainoo comes into things. His individual numbers are not good. However I have eyes. I can see that he’s got skills in some areas that United have been lacking in central midfield for years.

When was the last time United had a midfielder that could receive a pass under pressure like this and turn forward with it?

The kid is the real deal. So he doesn’t have much passing in his pocket. Every time I watch him play he reminds me of prime Matic - with much more potential. He’s someone that holds his position to protect the back four. When he gets the ball he’s composed and looking to move it to someone who can be more dangerous with it them himself.

Defensively he’s making an impact in United’s numbers. Since his debut against Everton their expected goals against and goals against are lower when he’s on the pitch. That’s despite the fact that they’re often leaving him isolated out of possession.

The attacking numbers aren’t much different whether he’s in or out. That’s a hint to look around him. He’s a facilitator who needs to be flanked by ball movers but he’s not. When the ball does get forward United’s attacking structure doesn’t get the best out of their players so they’re struggling.

Kobbie Mainoo is very good. Numbers are also good. You want to know if someone is good? You’re going to need to watch them to find out. The numbers will help tell you where to look, and what to look for.

1. There’s a lot of truth to this one and it merits it’s own post but it also involves a truth that Manchester United fans really don’t want to face right now

2. Garnacho has only has three shot-assists for Rasmus Hojlund in the Premier League this season. That’s one fewer than Marcus Rashford. United’s inability to get the ball to their striker tell a big story about their attacking woes.