Full-time job: making video analysis for referees

“When I watched and analysed a game of Bjorn Kuipers, I am exhausted”, says John Balvers, he is making video analysis for referees in The Netherlands. Recently I met again with him and he shows me the latest features of his video analysis. In this interview with him he tells more how video analysis for professional referees works. 

Balvers goes back to 2016, as that was a very interesting year for him with a Dutch referee in a big European final. As soon Björn Kuipers got the appointment for the Europa League final he started with the preparation for that game. In the meantime Dennis Higler is officiating at the under 17 Euro’s. Busy days for the video analyst. In this interview he tells more about how he works.

Being a video analyst is John Balvers’ full time job, almost 24-7. Competition weekends last from Friday to Monday. And if there’s no international football there are some cup games. “There is always football, so always a referee to analyse.” During the European Championships in France he has a special role: helping Bjorn Kuipers analyse his game and the matches of the teams he’s going to officiate. “My goal is to prepare Team Kuipers to the best of my ability helping him reach the final.”

John Balvers making video analysis for referees

Preparation before the games

Balvers is a full-time video analyst for referees working for the KNVB, the Dutch football association. He helps all referees at the professional levels and this period he’s totally focused on the Euro 2016. He took his holidays right before the tournament started and tries to watch as many games as possible. “What I do is unique and doesn’t happen in many other countries, definitely not with a full-time video analyst specifically for referees.” Check video in Dutch made by KNVB about John Balvers.

Every day during Euro 2016 Balvers waits for the moment new match appointments are published by Uefa. Sunday morning Uefa announced that Kuipers will officiate the clash between Spain and Croatia for next Tuesday. “Bjorn will notify me as soon as possible”, says Balvers. “The sooner I know which game he’ll officiate, the more time I have to make a video analysis for referees. I’ll arrange with Bjorn what he needs for his preparation.” When officiating the Europa League semi-final between Sevilla and Sjachtar Donetsk, Balvers analysed their latest encounters in both European and national competitions.

In the preparation of Kuipers’ games Balvers is collaborating with Jaap Uilenberg, the coach of the Dutch referee and also an Uefa referee observer. “We’ve also selected the video clips for the refereeing training camp before the Euro’s together”, he says.

John Balvers' video lab.

The video analysis for referees

The analysis of Balvers is very comprehensive. He’s in his video lab at home and will watch all games and digitally types almost every detail of the game. If there’s a challenge, which player made a foul, who suffered the foul, where free kicks are, who take them, if corner kicks are swung in our out,  which players get the ball often. “With all those stats you recognize how a team plays tactically and builds-up their attack or defence”, says Balvers. “Players often react the same way. In the game against Sevilla the Shakhtar Donetsk players took their corner kicks with short pass to a team mate. As referee you need to be aware that players that things will happen  around the corner flag.” It gives the referee an idea where his focus (also) should be.

All the data Balvers creates will be added to a video database which can be searched through by the match officials. Because there’s lots of data, Kuipers and other Dutch referees, can check attacks from a specific team, challenges from or on a certain player. All easy accessible for them. “I also have data  about who’s on the receiving end of the fouls, so referees are able to check the reactions of players. It shows who has temper, so refs can anticipate on that by calming him down immediately.”

Live analysis during the game

During games of Dutch referees Balvers will be analysing the performance and decisions in real-time. “It’s easy to do it live with all the video streams I can watch”, says Balvers. “I can even watch all replays immediately. Every situation that is possibly interesting for Team Kuipers will be send to them during the first half. Short clips about ten to twelve seconds or freezing frames for the assistant referees with offside calls. So the refereeing team can see if they made the right decisions.”

Two years ago PSV attacker Luuk de Jong scored against Feyenoord, but replays showed he hold the shirt of defender Kongolo. “Kuipers went to Feyenoord captain Clasie during half-time and admitted his mistake and said sorry to him”, Balvers explains. “I send them all clips that seem interesting to me. Right or wrong decision. Kuipers really wants to know if he made a mistake. I don’t give my interepratation, I only send them the video clips. My opinion is not important.”

In the image below you can see all tags Balvers made during a game of the Spanish team against the Czech Republic. All yellow cards (gele kaarten), challenges (duels), offsides (buitenspel) are tagged and Kuipers can check certain types of situations (only left wing attacks or so).

Coding all match situation for Team Kuipers.

Clips on the iPhone

Sometimes Kuipers will even get more than ten clips. “It’s up to him if he wants to see them. He can easily access them on his iPhone or on an iPad in the dressing room.” See image below for clips on the mobile device.

After the second half the refereeing team get some clips as well. At big tournaments the complete analysis with detailed descriptions will be made. “Most of the time the analysis will be ready by the end of the day”, says Balvers. After Kuipers’ games during the World Cup in Brazil he had to fly over 3 hours to the home base for referees. “Then I tried to get everything ready before they stepped into the plane, so they can check everything in the airplane and are briefed when they land.”

Balvers tries to work as fast as possible. He also helps referees during regular games in the national competitions, sends clips to Dutch referee boss Dick van Egmond or Uefa referee observer Jaap Uilenberg. Or to Danny Makkelie in the middle of the night during the u17 World Cup in Chile. “As soon as I hear their appointments I’ll start collecting data and clips.”

After the game it’s now even possible to add the communication of the referees via their headset to the video analysis. “With the headset info referees can improve the way they communicatie with each other.” That’s something that has improved the most in Team Kuipers during the last years together with Sander van Roekel and Erwin Zeinstra, his assistants.

Read interview with Bjorn Kuipers about progression his team made.

Video analysis on a mobile device.

Big library

All those analysed clips together form an interesting library for referees. “It’s accessible for everybody who’s involved in refereeing of professional football in The Netherlands.”

Via a new system called My Team Performance Exchange (MY TPE) it’s even possible that referees select the clips they want their team to study. “He can send them to his team members as match preparation and ask them for a comment on it.”

Watching games normally

“I can’t watch football normally anymore”, says Balvers. He is analysing everything. It was hard for Balvers watching the game between The Netherlands and Costa Rica during the 2014 World Cup in Brazil. In case the Dutch lost, Kuipers might officiate the Costa Ricans in a future round and Balvers was already doing his analysis on the games so it would be ready when the appointments were made. “It felt like the world collapsed”, he admits. “I am a huge fan of the Dutch national team, but I work during a big tournament for Team Kuipers. All I hoped for was them reaching the final. I’ll do everything during the European Championships to help them prepare the best way possible and I hope it helps them reaching the final.”

Read more from Euro 2016 referees

Different types of referee training

Different types of referee training will make you fit enough to referee. But what are the differences and how do they help you? In this blog post I’ll share 4 types of referee training sessions and the effect they will have.

Football is a sport where interval training seems the most logical way to train. The tempo of the game changes a lot, because the ball goes out or players run faster during an attack. But that doesn’t mean you should do only endurance training seassions. There is more and all are functional for you as referee.

After doing a proper warm-up there are 4 types, from low to high-intensity, are:

  • Extensive endurance training
  • Intensive endurance training
  • Extensive interval training
  • Intensive interval training

4 types of referee training

Extensive endurance training

If you follow an extensive endurance training you train at low intensity, but usually for a longer time. Because of the duration of the training you’ll get fatigued.

I shared an example of this type of training in the pre-season fitness tips for referees.

KNVB’s refere fitness trainer says: “The effect is improvement of your basic endurance and fat burning. Your feeling during the exercises: easy breating, low intensity for muscles and low levels of sweat loss.

Intensive endurance training

The intensive endurance training is a bit quicker than the extensive endurance traning, but still no sprinting. The duration of exercises are a bit shorter and the tempo a little higher. But the idea is that you don’t have big speed differences in the exercises. So you’ll remain at a continious tempo.

KNVB’s refere fitness trainer says: “The effect is that you improve your endurance. And your feeling during the exercises: low intensity for muscles, easy breathing and average sweat loss.

Extensive interval training

Now we’re getting faster. The extensive interval training will have more sprints. If you use a heart rate monitor you’ll notices it goes up a little and the distance you’ll run are shorter.

KNVB’s refere fitness trainer says: “the effect is increased maximum performance level. And you’ll notice sore legs and heavy breathing.”

Intensive interval training

The intensive interval training is even faster than the previous type on the list. The distance is not always shorter, but speed and  heart rate is higher again. The breaks between the runs in a series are usually a bit longer.

KNVB’s refere fitness trainer says: “the effect is development of the maximum performance and speed. You’ll notice it’s very exhaustive for both breathing and muscles.”

Examples will follow during the upcoming weeks

Because the interval training sessions are at higher pace, it’s important to not repeat them too quick. KNVB’s advice is to take a recovery time of 24 hours for endurance training sessions and 72 hours for interval training sessions. But you should always listen to your own body and your own physical ability.

Examples of training

Substitute entering the field of play

A substitute entering the field of play: how do you deal with this? It’s a rare situation in the German leagues. What is your call?

It’s a situation described in one of my weekly Laws of the Game Quizzes. Below the video you’ll see how you need to handle.

The situation

In the German Second Bundesliga game between Holstein Kiel and VfL Bochum this rare accident happens. Kiel player Michael Eberwein is doing his warm-up behind the goal-line. Because the ball goes wide, he stops the ball to make it easier for the goalkeeper to grab it.

But what Eberwein doesn’t realise is that the ball did not wholly cross the line. This means the ball was still in play and he intereferes with play. The video referee calls over the referee to check the video footage.

LOTG on a substitute entering the field of play

The Laws of the Game are very clear on this:

“If a team official, substitute, substituted or sent-off player or outside agent enters the field of play, the referee must only stop play if there is interference with play.” Check!

“Have the person removed when play stops”. He already left.

“Take appropriate disciplinary action If play is stopped and the interference was by:

  • a team official, substitute, substituted or sent-off player, play restarts with a direct free kick or penalty kick
  • an outside agent, play restarts with a dropped ball If a ball is going into the goal and the interference does not prevent a defending player playing the ball, the goal is awarded if the ball enters the goal (even if contact was made with the ball) unless the interference was by the attacking team.

In this case a substituted interferes with play, which means play has to be restarted with a penalty kick.

The role of the video referee

But doesn’t this seem a minor offence? Yes, the ball would have gone out anyways. But as the restart would have been a penalty kick, it means VAR will take action.

Have a look in the German VAR center.

Proper warm-up for referees

A proper warm-up for referees is needed for both training sessions in games. It will improve your performance and reduces your risk of injury. 

The blog post is based on lessons I followed as a referee and notes I took. 

Warm-up for referees.

Physical effects of a warm-up

The physical effects of a proper warm-up for referees are:

  • Less stiffness in muscles and joints
  • More activity in nerve system, which means a better coordination
  • Better circulation of blood, so more oxygen to your muscles and you’ll easier get rid of (too many) lactic acids 

Mental effects of a warm-up

When you do a good warm-up:

  • You’ll be better focused mentally (more tips to stay focused)
  • You can adapt to the field conditions and know what you need to deal with. Plus you can pick the right clothing and shoes).
  • You get used to the match circumstances, like the fans and the pitch

What the real warm-up looks like

Because the effects are important, I’ve written them out below. You need to know what the benefits are for you, but I get that you want concrete tips to do your warm-up properly. 

  • 5 minutes of jogging
  • 5 minutes of mobilisation exercises. Examples are: tripling, skipping, moving sideways, moving backwards, cariocas, zigzag shuffling.
  • 5 minutes of accelerations (10 to 50m)
  • 5 minutes of dynamic stretching or core exercises. At my referee association in The Hague we do two different exercises of the dynamic stretches:
    • standing in an angle of 90 degrees on the fence. Hold it with one hand and move your leg forward and backwards (leg pendulum or forward leg swing)
    • standing in front of a fence and move the leg from left to right. You’ll find more online for standing leg swing sideways.
  • Examples of core exercises: stepping out and moving your knee out/in, jump forward or backward and land on one leg, lean on one leg and bend the knee. Check out core and stability exercises you can do at home.
  • 5 minutes of sprints
    • You can do a few sprints of 10, 20 or 30 metres. When you walk back, you get some rest as well.

Below you’ll see me check out the warm-up of the refereeing team at the TD Place in Ottawa.

Credits plus KNVB newsletter worth checking

The blog post is based on lessons I followed as a referee and notes I took. One part of these lessons were videos by pro referees fitness coach Hilco de Boer. KNVB has also a monthly newsletter with tips and fitness exercises. Subscribe via the KNVB website and pick KNVB Assist Scheidsrechters (the Dutch word for referees).