Summarize this content in well-structured paragraphs in German language and keep HTML tags Follow live coverage of Denmark vs England here. England are playing Denmark at Frankfurt’s Deutsche Bank Park in their second Euro 2024 match and UEFA has confirmed the roof will be closed for the Group C clash.The roof of the stadium had been closed on Wednesday before Denmark’s training session to save the pitch from expected overnight rain.On Thursday morning, it was then decided that the roof would remain closed for the match. UEFA said it was ‘a precautionary measure’, adding that opening and closing the roof was a significant operation.It is not the first time England have played under a roof at a major tournament, having also done so at the 2002 World Cup when they faced Argentina at the Sapporo Dome in Japan. England won that group-stage match 1-0 thanks to a penalty from David Beckham.In April, Manchester City’s Champions League quarter-final first leg against Real Madrid was played under the new roof at the Bernabeu after the home side had received permission from UEFA to do so. England midfielder Jude Bellingham played several games for Real under their roof last season, including his home debut for the club in September.But how common is this for football matches and across sports? And is there any controversy about it?
England beat Argentina at the 2002 World Cup under a roof at the Sapporo Dome in Japan (Stu Forster/Getty Images)Which other football stadiums in Europe have retractable roofs?Only a handful of major stadiums in Europe have retractable roofs.Schalke’s Veltins-Arena, Romania’s National Arena, the Friends Arena in Sweden, Vitesse Arnhem’s GelreDome, the Johan Cruyff Arena in Amsterdam and Zenit Saint Petersburg’s Gazprom Arena have retractable roofs.There are also roofs at the Merkur Spiel-Arena — of Fortuna Dusseldorf — Denmark’s Parken Stadium, Lille’s Stade Pierre-Mauroy, the Stadion Narodowy in Warsaw and Stockholm’s Tele2 Arena.Cardiff’s Millennium Stadium, which is primarily used for rugby union, has a retractable roof — more on that in a bit. And there are four tennis stadiums with retractable roofs: Centre Court and No 1 Court at Wimbledon, OWL Arena in Halle, Germany, and Stade Roland Garros in Paris.How does closing a roof impact other grass sports?The most comparable sport regularly played in a closed-roof stadium is probably the NFL. There are 10 stadiums in that league that either have fixed roofs or retractable ones.There has always been a sense that indoor stadiums lead to more points being scored. As The Athletic’s Hannah Vanbiber explained in January — before this year’s Super Bowl at the domed Allegiant Stadium in Las Vegas — indoor Super Bowls tend to be higher scoring than outdoor ones, with outdoor Super Bowls averaging 44.6 points. But the first 11 Super Bowls were outdoors, and many early Super Bowls were low-scoring.Using Super Bowl XII (1978), the first indoor Super Bowl, as a starting point, outdoor games have averaged 49.7 points per game since then, which is more than indoor games.The small sample size and different eras render these stats largely meaningless, but they may fight against the theory that indoor venues are ripe for many points.There is also the case of Jared Goff, the Detroit Lions quarterback. As of January this year, he had a 69 per cent pass completion rate in indoor venues, with a 64.5 per cent pass completion rate at outdoor venues. Playing indoors had an impact on him.Since the All England Lawn Tennis Club installed its roof at Wimbledon’s Centre Court in 2009, there has been a sense that it has impacted the air in the venue and made the ball move slower.
The closed roof at Centre Court during the 2023 Championships (Mike Hewitt/Getty Images)In 2011, Professor Steve Haake of Sheffield Hallam University’s department of sports engineering said to the Daily Mail: “The roof closes when it rains, and it takes 10 minutes to do so — that means the grass will still be damp.“This could fluff up the ball because the balls pick up the moisture from the ground. Even a small increase in its size will make it less aerodynamic and therefore slower. That would be the major factor.“Changes in temperature and humidity will also affect the flight of the ball. The colder the air, the thicker it becomes, and the slower the ball will travel. A drop of 5C (41F) in temperature increases the air density by two per cent.”He also explained that a lack of breeze also causes an issue with perspiration, as sweat will not evaporate as quickly. This makes players feel like it is more “hot and humid” than it really is.Wimbledon has an “air management” system designed to mitigate this, which is configured to emulate normal grass court tennis as closely as possible. In New York and Melbourne, at the U.S. Open and Australian Open, roof closures have recently protected players not from rain and humidity but from extreme heat by providing shade over the court.Is there any controversy around closing roofs at stadiums?Yes. Going back to the Principality Stadium, there are always huge issues around closing the stadium roof, especially for the bigger games during the rugby calendar.There have to be very specific conditions for the roof to be used. For Six Nations games, both sides have to agree on whether they want it closed or not before a closure can go ahead. This can cause off-pitch tension before the match.There is also a sense that the atmosphere benefits from the roof being closed — which can often be seen as a reason one team will not want the roof to be in use.For example, this February, Wales head coach Warren Gatland expressed anger at Scotland’s desire to keep the roof open despite rain being forecast, suggesting it was part of a plan to limit the impact of the Welsh crowd. In turn, Scotland head coach Gregor Townsend claimed that the ball can become “greasy” if the roof is closed.What have sports stars said about playing at stadiums with roofs?Former England rugby player James Haskell admitted that there was a clear impact from closing the roof at the Principality Stadium when his side played Wales.He said the atmosphere was much more powerful, and told WalesOnline: “If the roof is closed and you’re 10 metres from the Welsh line, or they’re 10 metres from your line, the noise becomes so oppressive it’s like a force on top of you.”
The roof closed at the Principality Stadium (Harry Trump/Getty Images)In tennis, the most notable recent match was the 2023 women’s Wimbledon final between Marketa Vondrousova and Ons Jabeur. The roof was closed pre-match — rather than the usual change of weather necessitating it — due to high winds.Vondrusova, who won, said: “I was really happy they closed the roof because it’s very different than in the windy weather.“The roof can help you with serve. You don’t have to focus on the wind so much. I feel like everything is the same on every side. You just have to focus on the game, not on the wind, not even on the sun.”Most tennis players prefer to use the roof as little as possible, despite the weather, because they are fundamentally meant to be playing outdoor events.(Top photo: Richard Pelham/Getty Images)