Field hockey moves into untested waters at the London Olympics as teams will be allowed to call for one video referral per game through on-field umpires, the International Hockey Federation (FIH) said.
"Since Beijing (2008 Games venue), the possibility for a team to request a referral has been included and so London will see this for the first time at an Olympics. Each team is allowed one team referral, which must be made through the match umpire. This can occur at any time during a match, including extra-time in classification matches, but not during shoot-outs. Only umpire referrals are permitted during a shoot-out," the FIH said on its website.
"Team referrals are restricted to decisions within the 23 metre areas relating to goals, penalty strokes and penalty corners. Penalty cards may not be the subject of a team referral," it added.
Pointing out that in addition the umpires can also ask for referrals as is already the case since the Beijing Games, the website said that a video umpire will be in operation for all the men's and women's matches held "on the main competition pitch".
"Video umpire was first used in the Olympics in Beijing. At that time, it was only the umpires that could initiate a referral. These umpire referrals will still be in operation in London, whereby the umpires can refer decisions to a video umpire when they are not convinced that they have made or can make the correct decision about awarding or disallowing a goal. This includes whether a breach of the rules has taken place within the attacking 23 metre area in the play leading to the goal."
Any player on the pitch at the time of the incident can request for a referral by using the 'T' sign to alert the umpire who will then ask the video umpire to ask for the replays "from the available camera angles and gives the recommendation to the match umpire. The final decision always rests with the match umpire".
"If a team referral is upheld, the referring team retains its right of referral.
"If the video footage is inconclusive -- not having the correct angles available, the ball never being in shot in the replays, the footage being of insufficient quality to permit a decision or technical problems with the referral equipment -- the referring team retains its right of referral. If there is no clear reason to change the umpire's original decision, the referring team loses its right of referral for that match," the website said.
The technology for the replay system will be provided by the UK-based firm Hawk-Eye which first made its name in cricket and has since diversified across other sports including tennis and now football, the website added.
The men's hockey competition, featuring India and 11 other teams, will be held from July 30 to August 11, while the 12-team women's tournament, not featuring India, is from July 29 to August 10.
Image: A general view of the blue turf at the LOCOG Test Event for London 2012 at Riverbank Arena - Hockey Centre
Photograph: Bryn Lennon/Getty Images