Wimbledon tennis players: Grunting pitch 'reveals champs'
A low-pitched grunt is a winning giveaway in tennis, a study has shown.
As Wimbledon warms up, University of Sussex researchers say they have found the pitch of grunts can help predict who will win a match.
Footage was analysed from 50 matches featuring some of the world's top 30 players and showed grunts were higher pitched in matches they lost.
Researchers said they could often predict the match winner from listening to players' grunts.
Grunts from both male and female players were measured during serves, backhand and forehand shots by researcher Jordan Raine, together with mammal communication experts Professor David Reby and Dr Kasia Pisanski.
They recorded at what stage of each match the grunts were produced, as well as whether the players won or lost the match.
While the pitch generally increased as matches progressed, the study, published in the journal Animal Behaviour, found the likely match outcome was often apparent from the outset.
Mr Raine, who is also university tennis team captain, said this suggested shifts in pitch may reflect longer term physiological or psychological factors, including a players' "previous encounters, form, world ranking, fatigue, and injuries".
'Dog, deer or Djokovic'
But he added it could be something many players have tuned into for a long time, with the form of non-verbal communication linked with an animalistic display of dominance.
When a selection of the athletes were played short clips of other players' grunts with no other information, they could tell which of two grunt sequences produced by the same player came from a match that the player lost.
Mr Raine added: "Male red deer use the roars of competing males to assess their size, and therefore who is likely to emerge from conflict victorious. Humans are no exception."
He said that because "anatomy and physiology affect the vocal apparatus of all mammals in the same way", the noise animals made inadvertently gave others clues about their "physical attributes and internal state, whether dog, deer, or Novak Djokovic".
Grunting has been a controversial part of tennis for a number of years, the 1990s Yugoslav champion Monica Seles was an early culprit, and competitor Martina Navratilova was one of many to complain about her shrieks.
Former world number one Maria Sharapova and Rafael Nadal are also regarded as grunters. Roger Federer has complained about Nadal's noises in the past.