PV Sindhu spars with Ayush Shetty at the Indira Gandhi Indoor Stadium. (Photo: Tanuj Lakhina)New Delhi: In badminton, a point, a set, a match and, by extension, a title, can be decided not just by a drop shot, a smash or a fake at the net. External factors such as the weather, the draft and humidity play a huge role. And that could test the players when the BWF World Championships get underway in New Delhi on Monday.With Delhi facing irregular monsoon showers and humidity hovering between 70% and 90%, the air conditioners would be cranked up over the course of the week, with the best in the business already in India. Even the non-toxic gel that has been installed to keep pigeons at bay at the Indira Gandhi Indoor Stadium needs a certain temperature. If the arena gets warm, the gel will lose consistency and drop onto the seats below.As players arrived and practised at both the main hall and the adjacent KD Jadhav Indoor Stadium, some were met with stiff conditions, while others encountered subtle winds.A Chinese doubles shuttler mentioned that the current conditions feel different compared to the India Open in January, even though it is the same venue.Tokyo Olympics gold medallist Chen Yu Fei, who has won multiple World Championships medals but never gone all the way, stressed that she has not had the time to test the courts yet. World No. 3 Wang Zhi Yi said she noticed some movement in the air and emphasised that adjusting to the drift would be key.I just finished my training; I feel like there was a little bit of wind on the court, so we need to get used to the conditions.Wang Zhi Yi“For sure, I think the stadium has changed a lot; that's very good. I just finished my training; I feel like there was a little bit of wind on the court, so we need to get used to the conditions,” Wang told the media in the mixed zone.Even a modest draft from the air conditioning, fans, doors or ventilation can push the shuttle off its intended path. This affects clears, lifts, drops and smashes, so players may need to aim differently or use more controlled shots.Shuttlers going through the paces at the Indira Gandhi Indoor Stadium. (Tanuj Lakhina)Not everyone is complaining, though. World No. 7 Li Shifeng was pleased with how the court was behaving and landed a proverbial pat on the back for the organisers.“The size of the court is really good. I feel like the drift and all and everything, the weather including that, everything is very well maintained and very good as compared to the last time. So yeah, it's a very good place, and even the venue is very well maintained and good,” said the 26-year-old.Beyond the draft from the air conditioner, the temperature and humidity may make things trickier for the players. Over the next week, the mercury is expected to read just over 30 degrees Celsius, with humidity making things even tougher.Indian shuttlers going through the final touches at the Indira Gandhi Indoor Stadium in New Delhi. (Photo: Tanuj Lakhina)The two factors change air density and, therefore, shuttle speed. A shuttle may travel faster in some conditions and slower in others, requiring players to adjust their power and timing. Humidity and heat also increase fatigue and dehydration risk.So when the BWF World Championships begin on Monday, watch out for the weather, the humidity and the AC, not just the speed of the smash.