HAWKEYE - 4 CHALLENGES

Players will be allowed up to four unsuccessful challenges per set at any tournament that uses electronic line calling systems, tennis officials said on Wednesday.

Since the arrival of electronic line-calling review systems -- using Hawkeye technology -- tournaments have been allowed to set their own rules for using the system.

While some allowed players to have an unlimited number of challenges in every match, other tournaments limited them to two or three unsuccessful challenges per set.

The governing bodies said players and teams would now be allowed a maximum of three unsuccessful challenges per set plus one more if the set reached a tiebreak.

Next week's Sony Ericsson Open in Miami will be the first tournament to use the unified challenge system.

Three of the four grand slams use the technology. The French Open is the only major not to use the system as the ball leaves a mark on the clay surface.

The attitude of the French Open baffles me!

I've seen videos [Mac cam, no less] of a serve hitting the line, deforming, skidding off and then reforming and leaving a mark clear of the line.

C'EST INCROYABLE!