MONTREAL — When Ivo Karlovic was a lanky, young teenager, his daily routine took him to the Salata tennis club in Zagreb, Croatia, where he would fire hundreds of serves into an empty court.
It was during the war in the former Yugoslavia, and Karlovic said it was difficult to find other teenagers with whom to play. So Karlovic, from about age 15 to 16, would gather about 200 balls and launch them across the net while emulating his favorite player, the fellow Croat and big-serving Goran Ivanisevic.
Karlovic would then walk to the other side of the court, pick up the scattered balls and serve them back again — to no one.