The Australian Open's new balls this year are dividing opinion at Melbourne Park, with even the two greatest men's Grand Slam winners of all-time failing to see eye-to-eye.
Roger Federer, winner of 20 Slams, says the new Japanese-made Dunlop balls behave differently in cooler night conditions and do not allow players to "out-spin" rivals.
But Rafael Nadal, the 17-time major winner renowned for his huge top-spin groundstrokes, countered: "I can't say it's a bad ball." Australian John Millman reckoned "they're a bit heavy" after losing on Wednesday night while his big-mouth countryman Bernard Tomic pulled no punches, saying they were "dead" and "really shit" before he lost in the first round.
Tournament director Craig Tiley has defended the change from Wilson balls, claiming earlier in the week he had heard only "positive feedback".
He might have to change his mind after defending champion Federer offered a different opinion on Wednesday.
"Well, they definitely play a touch different to
