Paris, May 26 -- In a move that harks back to old guard of tennis, the French Open has become the last Grand Slam tournament to resist the tide of technology, retaining human line judges and refusing to implement automated line-calling systems on its courts this year. French Tennis Federation (FFT) President Gilles Moretton on Monday defended the tournament's decision to persist with traditional officiating, citing a recent controversy at the Madrid Open involving world No 3 Alexander Zverev. The German received a warning after asking the chair umpire to inspect a disputed mark on the clay, an appeal that was denied, prompting Zverev to take a photo with his phone in protest of a call made by the automated system. "This is important for us,...