There are very plausible reasons why Hawk-Eye technology is not utilised on clay courts to make line calls. The margin for error is presently too great, plus clay leaves a visible ball mark to enable umpires to jump down from their high chairs and verify questionable calls. Allegedly – since there have been plenty of hotly disputed line calls, many concerning whether, with so many potential ball marks visible, the umpire has even been checking the correct mark.
So, if you are someone who misses the good ole days of irate players taking out their frustrations on well meaning but fallible umpires and linespeople, then clay is your surface. If, however, you would prefer the drama to emanate from the tennis, then watching contentious line call disputes at clay court tournaments must seem depressingly regressive.
Now, interestingly, Hawk-Eye is not foolproof. It has an error margin of +/- 2.6mm. But, of course, it’s nigh on impossible to argue with a computer, especially an invisible one (though somehow, John McEnroe would, undoubtedly, have found a way). The most heartening aspect of Hawk-Eye’s presence in tennis has been the greatly reduced potential for line call disputes, which must be a blessed relief for anyone who used to be embarrassed, rather than enthralled, by the querulous antics of Messrs. McEnroe, Nastase, Connors, and their ilk. With Hawk-Eye it is psychologically easier for players and the public to accept its call, even with a margin for error, because it is perceived as consistent and unbiased. It offers no scope for argument. The outcome is accepted and everyone moves on.
Except for clay court tournaments. Unfortunately, the presence of visible ball marks on clay will always serve to undermine any technology with an error margin, no matter how fractional. Possibly the most viable alternative may be to discover suitable technology for correctly identifying ball marks to help umpires resolve at least one obvious area of dispute on clay.
Then we can all be free to focus on other areas of arbitrary umpiring, such as the time taken between points. But that’s a whole new argument for a whole new post.