Introduction of neutral umpires in Test cricket has led to a drop in the number of Leg Before Wicket (LBW) decisions going in favour of home teams, a new study led by an Indian-origin researcher has found.
The findings come amidst renewed debate on whether neutral umpiring is still required in Test matches following the introduction of the Decision Review System (DRS), researchers said.
Dr Abhinav Sacheti and Professor David Paton from Nottingham University Business School and Dr Ian Gregory-Smith from the University of Sheffield analysed LBW decisions in exactly 1,000 Test matches that took place between 1986 and 2012 - nearly half of Test matches ever played in the history of cricket.
Until 1994, both umpires in Test matches were from the same country as the home team. From 1994 to 2002, one of the two umpires was required to be from a neutral country and after 2002 both umpires were required to be neutral.
Researchers found clear evidence of fewer decisions in favour of home teams with neutral umpires.
"Our results suggest that when two home umpires officiated in Test matches, away teams were likely to suffer on average 16 per cent more LBW decisions than home teams. When the ICC introduced the one neutral umpire policy, this advantage to home teams receded to 10 per cent," Sacheti, lead author of the study, said.
"When two neutral umpires were required in every Test match, this advantage to home teams disappeared. This result holds even when we control for the quality of teams, the ground where the match was played and so on," said Sacheti.
The researchers found that the bias by home umpires in favour of home teams had been particularly strong in Test matches played in Australia, India, Pakistan and Sri Lanka.
A possible explanation for the finding is that home umpires were unduly influenced by pressure from local crowds and, indeed, a similar bias towards home teams has been noted amongst football referees, researchers said.
Many cricket fans have long claimed that home umpires are biased towards their own team and the findings of this latest research appear to provide support for such claims.
"The results do not necessarily mean that umpires deliberately favoured their home teams - the bias may have been unconscious. The fact remains though that introducing neutral umpires seemed to get rid of the problem," Paton said.
Recently, some commentators have suggested that the introduction of the DRS eliminates the need for neutral umpires, said researchers.
The study was published in the Journal of the Royal Statistical Society.
