For a man who’s served two clubs rich in tradition — Liverpool and Spurs — Damien Comolli is no prisoner of the past. The burgeoning world of data and analytics isn’t just familiar to Comolli: he’s passionate about it.
“It’s got to a point where I’m frustrated by what I can’t measure, or get people to measure for me. I’m not a geek at all, I’m bad with numbers, but I do understand how to use numbers in football.
“More and more I see situations in games and think, ‘can we measure that, can we go beyond what we do?’ And that’s been in my mind for almost 15 years now.”
That doesn’t mean he rules out the power of the coach’s intuition, though: “The one thing I’ve found is that the top, top coaches — the world-class coaches — their intuition is so good, that they’re matching what the data says. Someone like Arsene Wenger is showing me that when you measure it, his intuition is right.
“That’s not the case every time. Not every manager is Wenger, or Jose Mourinho, or Alex Ferguson, but what’s interesting is that the people I speak to in baseball and basketball and so on say the same thing — the top coaches in those sports have been doing things that the data now backs up.
“Yes, a substitution during a game by a top coach may be based on intuition, but our role is to bring the elements to that decision which are backed up by nutrition and so on, and you can reach a point where the coach says, ‘well, I’m not sure about this but the data says this so that’s what we’ll do’.”
Is there resistance to or acceptance of data, though, at the top level?
“It’s both — there’s strong resistance from some in the game while others buy into it totally.
“It’s not about their age or their past, whether they were good players or not, it’s whether or not they believe in it. But I definitely think it’s a trend we’ll see going forward.
“Game management is going to become bigger and bigger — when to make substitutions, and so on — and when it comes to tracking data live, for fitness and so on, then it will become even more important.
“There’s also recruitment, which is a huge aspect of this as we are getting access to more and more leagues and their data. When I started, we had information on maybe five leagues, but now we have a lot of leagues, a lot of different age groups.
“Then there’s performance and injury prevention, fatigue study — we started to do that at Liverpool and I’m a strong believer in data helping us prevent injuries in players from the age of 22, 23 onwards.”
Comolli feels strongly about the dangers of overloading young players with training.
“They may be strong physically and mentally, but they can’t sustain the load we put on them. You’ll hear staff saying ‘we can train him, he’s strong, he doesn’t break down’, so between the ages of 12 and 18, 20 we train him and train him — but when he comes into the first team at 23, he starts to break down.
“The next step in physical preparation is measuring the load a young player can take so that when he reaches 23 and becomes the mature player, you want to rely on, then he’ll go on for 10 years, not five.”
The reality of the marketplace means clubs aren’t likely to share that information (“That’s a little like NASA giving away their secrets,”) but there are alternatives to simply getting that data:
“You can give a new signing a medical questionnaire and there’s also access to his playing record from the age of 17, so you can put two and two together and see if there are issues.
“Michael Owen is a good example. If you look at him at 23 he had a fantastic record, no injuries, fantastic — but then he starts to break down and you don’t have a way to access the load he’s been taking.”
Would he have had a longer career if that data had been available? “100%. With the right training and playing load at certain ages, he’d have had a very different career.
“He’s not the only one. Arsene Wenger came out a few times and said that while he was careful with the player and rested him at times, that he put too much of a load on Cesc Fabregas too early, in training and games, and that that was the reason he got hamstring problems later on — and that he (Wenger) would have done things differently if he had the chance again.
“At Liverpool we had devices to measure player load, ones they wore 24/7 to measure sleeping patterns, recovery and so on. We had five and tried them on young players. At the time, John Flanagan was in the first team, he was 18 but playing quite a lot.
“What we found out went totally against everything I’ve heard since I was brought up in football, that young players can play more because they recover quicker.
“Rubbish. We found that John Flanagan’s heart-rate was coming back to normal 72 hours after a 90 game, whereas a senior player was coming back to normal 24-36 hours later.
“That meant the risk of breaking down for him, if we played him within 72 hours of that game, was massive.
“That kind of data is going to be huge in the future.”
That said, doesn’t everything balance out when everyone has all the data?
“The logical answer is ‘yes’ but experience says ‘no’. When you look at what Billy (Beane) is doing with the A’s in baseball, everyone is doing it (analysing data) but the A’s are still winning most games in baseball though they’re second from bottom in their wage bill.
“In the future. if the club has the culture to believe in data, that will make a massive difference.
“There are things you can’t measure, things like team chemistry, like the club guessing a player will adapt to a certain culture, city, way of playing — that remains a massive competitive advantage.
“Another part of competitive advantage is the club’s manager and coach and their ability to give the player confidence.”
What about a manager like Harry Redknapp, not known for his love of sports science?
“The people behind him tell him what to do,” says Comolli.
“I’m exaggerating, but when he wanted to sell Gareth Bale, they offered him to the whole world. The sports scientists at the club said they were looking at noise, not signal, and Harry said in his first 24 games for Spurs they hadn’t won a game, so he wanted to get rid of him.
“The stats guys said he was looking at the wrong data and that he was playing Bale in the wrong position, that he needed to be in left midfield. Bale was on the way to Forest on loan, Spurs had injuries, and they call him on the motorway to come back.
“Harry, though, put faith in Bale and gave him confidence. Which comes back to competitive advantage. Harry gave him confidence, told him he was the best in the world, and Bale felt 10 foot tall, so that was the difference Harry made.”