On 18 October 2013, in a Bundesliga match between Hoffenheim and Leverkusen, Stefan Kießling headed the ball into the side netting. It went through a hole in the net, and the referee gave a goal. The DFB sports court rejected Hoffenheim’s protest, because the referee’s decision on the facts is final. In spring 2014, the Bundesliga clubs voted on goal-line technology, and the proposal clearly failed. Cologne’s manager said the costs were too high to carry. That summer, the system was used in all twelve stadiums of the World Cup in Brazil. In December 2014, the clubs voted for it with a two-thirds majority. It has been used in the Bundesliga since the 2015–16 season.