What Is a Substitution Analyst?

In 2021, Sammy Lander contacted AFC Wimbledon with a proposition. He told them he could improve the impact of their substitutions. 

The club invited him to make a presentation. Lander had spent the previous season studying substitutions. He had gathered data about how often a substitute scored a goal or got an assist and created charts looking at how much time it took for a substitute to have an impact on the game. “The stats he showed us from last season told us we could make marginal gains from it,” explained coach Rob Tuvey. “In sport, you have to look at that.”

The club gave Lander a part-time trial to demonstrate whether he could put his ideas into practice. He’d previously worked as an analyst and coach at Weymouth and as a scout and analyst with Bournemouth’s academy, but this was his first time working on substitutions. He quickly made a difference. By the end of the season, the club had scored the second highest percentage of goals directly involving a substitute in the league.

Lander is part of a growing trend of specialist analysts and coaches in football. In recent seasons, clubs have hired specialists with a focus on previously neglected parts of the game such as throw-ins and restarts. Lander is the first to focus on substitutions. 

How a Substitution Analyst Helps Substitutes to Prepare

There are two main elements to what a substitution analyst does. The first is preparing the players on the bench so that they’re ready to come on and make an immediate impact. This involves preparing them both physically and mentally.

At Wimbledon, Lander worked with the substitutes to make sure they were warmed up and ready to play when needed. He devised various exercises and routines that he put the players through, including getting them onto the pitch at half-time to work with the ball. The aim was to make it easier for them when they took their first touches on the pitch against opponents who were already up to speed.  “It’s like if you haven’t driven for a week and that first change of gear isn’t as smooth as if you’d been driving for 100 miles,” Lander has said. “It’s the same for football.” He used the GPS vests worn by the players to monitor whether they were warmed up enough or if they needed to do some more exercises before being brought on.

As well as getting them ready physically, Lander also worked on making sure that the players had the right attitude and were mentally prepared. Often when a player hears that they’re not in the starting line up, they feel disappointed. Lander helped them to focus on the positive contribution they could still make to the team.

“We call them ‘finishers’, not substitutes, because even the word ‘substitution’ is negative. It means you’re second,” he explained. A player on the bench may not be one of the starters, but they can still make a big difference on the pitch at a crucial time. After all, what matters is the score at the finish of the game, not the start. Changing the language used when talking about the role helped emphasise this point.

As well as improving their morale, he also found ways to keep the players mentally involved in the game. He would regularly talk to the players about what was happening on the pitch. “I did opposition analysis so I could drip-feed that from the bench” Lander said. He also discussed any tactical changes that had been made during the game. Not only did it keep the “finishers” focussed, it also helped them to understand what was required of them tactically when they did come on.

Deciding When to Make a Substitution

The second main element of substitution analysis is working with the coaching staff to help decide when to make a substitution and who to bring on. This involves studying when a change is likely to have the biggest effect.

“We’ve got loads of different concepts and one of them is what we call impact times of players when they sort of best hit their peak performance or how long they average a certain KPI (Key Performance Indicators),” Lander has said.

Knowing the impact time of a player will help get the best out of them. If a player needs at least 15 minutes to make an impact, it won’t be effective to bring them on with just five minutes to go. Likewise, if a player averages an important KPI for just 20 minutes, it makes sense to wait until at least the 70th minute to bring them on if they’re going to have maximum impact.

The manager or head coach is still the one who makes the final decision about a substitution, but feedback from an analyst can help them make a more informed choice.

Which Clubs Are Using Substitution Analysts?

Following Lander’s success at Wimbledon, he now works as a freelance substitution consultant. He’s shared his insights with a broad range of teams across the Premier League, Football League, MLS, Scottish Premiership, Ligue 1 and Primeira Liga, although he doesn’t name specific clubs. His services are clearly in demand.

Other people working in football are starting to use data to help them make better substitutions. It’s already happening at Brentford, a club known for embracing data. The Premier League club doesn’t yet have a specialist substitution analyst, but their sports scientist Matthew King has explained how the club uses data collected from the GPS vests worn by the players to help assess when to make a substitution. 

Sat alongside manager Thomas Frank during matches, Head of Athletic Performance Chris Haslam keeps a close eye on the live data using an iPad. He tracks key metrics and when a player’s performance levels start to dip, he can inform the manager.

“Chris is on the bench for games and Thomas trusts him,” King has said. ”Thomas will turn around to him and go, ‘How is this player looking?’ At no point are we going to make a substitution entirely based on the data, but it’s one of the areas we can use to influence our decisions.”

The Future of Substitution Analysis

With so much data available, it makes sense for clubs to use it to improve the impact of their substitutions. It’s a part of the game that continues to grow in importance. In the first season of the Premier League, there were just three players on the bench and the manager was only allowed to make two changes. Now, teams are allowed to make as many as five substitutions. That means that half of the outfield players can be replaced. There’s a lot of opportunity for altering the outcome of a game with smart decision making.

Lander is currently leading the field, but it’s a new topic for analysts to look at and others are sure to follow in his wake. When asked about the future of coaching and analysis, Lander has said, “I believe specialisation is a way forward because the more you investigate something, the more consistent and deliberate you can be with it. And that’s how you get to be effective at something.” To succeed in football, a club needs to pay attention to every part of the game, however small it might seem. The little gains a specialist analyst can provide can make a big difference.