During the 2013-14 season, the KNVB deployed additional assistant referees, known as 5th and 6th officials during the Johan Cruyff Shield, the KNVB Cup semi-finals and final, and the Eredivisie play-off finals. The deployment was part of the KNVB’s Arbitrage 2.0 pilot scheme
The deployment of 5th and 6th officials has multiple advantages. It offers better control of the game and enables the assistant referees to focus on off-side. And it increases the number of correct refereeing decisions inside the penalty area.
Assistant referees are able to focus on off-side
In the ten matches in which they were deployed during the 2013-14 season, the 5th and 6th officials provided advise and support to the referee when a decision had to be taken. During the second year of the pilot, the KNVB raised the number of matches in which these additional assistant referees were deployed so that they could gain more experience.
At the European level, UEFA has been experimenting with 5th and 6th officials during Champions League and Europa League fixtures since 2009.