There always seems to be a new, bigger, better serve out there on the men’s tour. Over the last couple years, we’ve seen Ivo Karlovic make himself virtually unbreakable, while Sam Querrey has hit 10 aces in a row. But the serve du jour belongs to American John Isner, who used it to win five straight third-set tiebreakers in Washington and to take a set from Mr. Unbeatable, Roger Federer, at the U.S. Open.

What do these three men have in common? They’re all giants—6-foot-10 (Karlovic), 6-foot-6 (Querrey), and 6-foo-9 (Isner). But it wasn’t all this way with the game’s biggest servers. Yes, height helps—little Michael Chang never cracked the 140 barrier, as far as we know. But the best servers through the years were not necessarily the tallest. They were long, lean, lanky, deceptively strong guys like Bill Tilden, Ellsworth Vines, Pancho Gonzalez, and Colin Dibley.

This wiry line of descent reached its apogee in the 1990s in the form of two men: One who used to his serve to anchor the most potent game in the history of tennis up to that point; the other used his to get him out of all sorts of trouble and maintain a Top 5 ranking despite not having any other truly outstanding qualities—unless you count craziness.

The former, as you may have guessed, was American Pete Sampras. His serve put the clamps down on his opponent right from the start. Even when he wasn’t cracking aces, no one took the guy on the other side of the net of a point as quickly. Sampras may have had the heaviest serve—a combination of speed and spin—in history. It helped make tennis simple and easy for him: Slide that thing on the line and the point was halfway over. No wonder he was so good for so long. He was doing most of the work with one shot.

His diametric opposite through the 90s, and often his rival at Wimbledon, was Croatia’s Goran Ivanisevic. A loony lefty, he had an even more lethal gun than Sampras. Ivanisevic didn’t hit it supernaturally hard, but his pure, lightning-fast delivery and deadly accuracy into all four corners of the service boxes made him a virtual ace machine. Rather than build his game out from his serve, the way Sampras did, Ivanisevic lived and died by it, and no one lived as well on one quick swing of the racquet.