Using data to optimize performance in soccer is not a totally new trend; in fact the first known experiment of statistical analysis was carried out in the 1950’s by Charles Reep [https://en.wikipedia.org/wiki/Charles_Reep]. Even if they were very simplistic compare to nowadays standards, they were the starting point and they permitted Reep to establish a general principle that is still true today and states that past performance is a good indicator of future performance. It wasn’t until the late 1990’s that soccer teams started a more systematic use of video and data collection and it certainly took a new turn in the past few years with the introduction of new monitoring devices designed for the athletes and able to collect and process incredible amounts of data with a unbeatable accuracy.

During last World Cup in Brazil, Germany the future winner of the championship revealed that the national team wore Adidas miCoach elite team system during training sessions. The monitoring device was able to collect data directly from the athlete’s bodies such as heart rate, distance, speed, or acceleration and display those metrics on an iPad. And even if this data doesn’t give (yet) the solution to win a match, it gives a pretty accurate overview of a player fitness level. Trainers and coaches were able to personalize training sessions and were more precise when it came to make choices by selecting players for a game. They also used Match Insights, a system they developed with the local software company SAP. The football pitch is circled with cameras, precisely capturing the movements of every player. These were then broken down into individual performance metrics and built up again to show a tactical picture which could be compared against opposing teams. And as soccer players are known to love soccer video games, the information are presented in the same way they are in those playful applications. Before Match Insights was deployed in 2010, one of the Mannschaft weaknesses was a reluctance to pass the ball. Possession time was 3.4 seconds but by 2014, it had been reduced to 1.1 seconds.

And the German National Team is no exception. More recently, the latest success of data analysis in soccer is undoubtedly the british team of Leicester who managed to win the Premier League after starting the season with bookmakers offering odds of 5000 against 1. One of their many secrets was the use of Prozone [http://prozonesports.stats.com/] wearables during training sessions and the processing of the data with the Prozone 3 analytic tool. It allowed the team to customize training sessions to obtain the best of each athlete individually while reducing the risks of injuries. An important point as most of the soccer specialists explain Leicester’s achievement by the extraordinary small number of injuries suffered by the team during this season.

With a system very similar to the German Match Insight, all 20 Premier League football stadiums in the United Kingdom are equipped with 8 to 10 digital cameras that track every player on the field. Ten data points are collected for each of the 22 players every second, generating 1.4 million data points per game. British clubs are investing more and more to compete in this data-rich soccer environment and companies like Prozone are helping them to do so. That’s probably the reason Leicester did not put all its eggs in one basket and also used the OptimEye S5 from Catapult Sports [http://www.catapultsports.com/]. This mini GPS combined with an accelerometer, a gyroscope and a compass was attached to the back of every player. The data collected thru this device was used to model the workload bearable by each player and prevent over training. As a result, Leicester’s trainer Claudio Ranieri – who was called the Tinkerman for his switching habits when he was in charge of Chelsea – was able to use almost the same players during most of the season.

The team also used the suite of analytical products developed by OptaPro, a solution providing interactive reports available on iPad before, after and during a game. In his King Power Stadium, Leicester has a “war room” for its data analysts connected to the locker room so players and staff can have halftime statistics.

“This allows us to highlight the key points,” said Leicester Chief Analyst Peter Clark. “If a player loses his duels one against one, or aerial duels for example, this can help the coach. We can also focus on a type of situation that has consistently brought the danger to the opponent; this also can help the coach. “said Clark.

Today, it is still hard to evaluate what real advantage will come from the intensive use of data collection. Bookmakers as William Hill who admitted losing more than 10 million £ are probably going to catch up on big data and its implications in the soccer field. But as we have seen in the recent UEFA Euro Championship success is often a matter of very small things. So any kind of advantage as small as it may be seems to worth it!