Players will have the chance to add further dramatic dimensions to marathon matches at next year's Australian Open by being allowed to question more line calls under new rules outlined by organisers on Thursday.
HawkEye video line-calling, where high-speed camera technology allows close calls to be accurately reviewed, will be used for the first time at Melbourne Park after its successful Grand Slam bow at the US Open in New York last August.
With the Flushing Meadows tournament using decisive set tie-breakers, the Australian Open will be the first Slam to use the system from six games all in the final set.
As at New York, players will be allowed two challenges per set with a correct challenge meaning the number stays at two while an incorrect question means the challenges fall to one.
At six games all in the final set at Melbourne, the 'challenge counter' will be reset so that both players have two left over the next 12 points regardless of previous challenges in the set.
Tennis Australia said the challenges would be reset every 12 games in the event of epic tussles such as the 2003 quarter-final between Younes El Aynaoui and Andy Roddick which went to 21-19 in the fifth.
"When matches go beyond six games all in the final set, players still have the safeguard of being able to turn to the technology in cases where a call is disputed," tournament director Craig Tiley said.
Giant screens at Rod Laver Arena will replay HawkEye's verdict on questionable calls to increase crowd participation in the concept, Tiley said.
The Australian Open, the first Grand Slam of 2007, is from January 15-28.
