DW: What was the main reason for the introduction of the video assistant referee (VAR) in the Bundesliga?

Hellmut Krug: The basic idea is to reduce injustice in football. Last season our referees made 104 incorrect decisions. Of those, 77 could have been corrected using a video assistant. Nowadays, many fans in the stands have a smartphone. They can see, very quickly, if a referee has made a mistake. The only guy who can't see is the ref himself. It would be very backward of us not to provide referees with some outside assistance.

When can the video assistant be called upon?

There are clear FIFA rules on this. Only four situations can be checked: goals, penalty appeals, red cards, and cases when a referee mistakenly shows a card to the wrong player.

When FIFA's body in charge of the rules of the game, the International Football Association Board (IFAB), started its VAR campaign, Germany's DFB and DFL were on board from day 1. Why?

The 2015/16 season was decisive. It was not a good campaign for our referees. Many mistakes were made that were difficult to explain to the public. That's why we said that we would take part. We want to be on the front lines, driving the new system forwards. Every participating national association should give feedback on its findings, and all these results will be assessed at the University of Leuven Belgium. In March 2018, FIFA plans to decide on how to proceed.

How have referees been prepared for the new technology?

We've been training our refs for more than a year. Referees get used to making snap decisions on the pitch themselves. Now they need to learn to evaluate, to interpret a situation on screen. It's a totally different job. Here, too, FIFA has issued clear guidelines. Every video referee must have officiated five "offline" games and five "online" games. Offline means that they have no contact to the ref in the stadium, online means they're in direct contact. On top of that, every referee must have officiated at least three games on pitch with the support of a video assistant. All of our match officials have met these requirements.

You were a referee yourself. It was always the case, during your active career and beyond, that referees would make the decision on the field - and that decision was final. When did you start seeing matters differently?

More and more money's at stake in football nowadays. Teams are fighting for promotion and against relegation; they're looking to qualify for Europe. Increasingly, referees have begun facing massive public criticism for their mistakes. That's when you have to start asking whether we can really stick to the old philosophy of the referee deciding and there being no chance for appeal or revision.  On top of that, consider the immensely improved technical options on pitch - with more than 20 cameras in the stadiums now. Given all of this, I actually found it quite easy to change my view rather quickly.

Football is starting to lose its universality. There are now differences between Bundesliga games and German Cup matches, or 2. Bundesliga games, and that's before we even mention the amateur divisions.

We are going to have to accept this. Goal line technology, for instance, is only provided in the top division. Perhaps one day it will become relevant for the 2. Bundesliga as well.

It's a question of money and of technical capabilities. With only three or four cameras in a stadium, you can't have an effective video assistant referee.

At the Confederations Cup, interventions by the video assistant often took a long time. Will it be quicker in the Bundesliga?

I'm sure of that. When we started the tests it took an average of 90 seconds until a video assistant had checked a situation. Today, we tend to need between 10 and 30 seconds. But these Confed Cup delays were easy to predict. There was no chance to properly train the referees beforehand. They only had four to six weeks to get used to it all. On top of that, the referee and their video assistants did not know each other. Our colleagues know each other, that forms a basis of trust. The man on the pitch knows he can rely on the monitors. That's why Bundesliga referees will only use the "review area" on the sidelines, to see replays of the incident themselves, in exceptional cases.

How are you feeling ahead of the first Bundesliga weekend with VAR?

We have done everything that we could. Now we need to start gathering data from practical experience. Everything will not go off without a hitch. There will surely be the odd incident that calls for revision. But I am sure that the video assistant referee will lead to more justice on the pitch. And the fans will recognize that.

Hellmut Krug was a DFB referee from 1984 to 2003 and was named an international FIFA referee in 1991. He headed up the DFB's refereeing division until 2007. Currently he's in charge of the DFB's and DFL's project to introduce video assistant referees in top-flight German Bundesliga matches.

Herbert Schalling conducted the interview.