Andy Roddick's serve speed to Rhyne Williams is displayed at...

Andy Roddick's serve speed to Rhyne Williams is displayed at 128 mph during first round play at the 2012 US Open Tennis tournament. (Aug. 28, 2012) Credit: Kathleen Malone-Van Dyke

At the big tennis county fair that is the U.S. Open, folks always want to see the strong-man competition, an equivalent to muscular brutes armed with mallets attempting to ring the bell at the top of a small tower. Thus the popularity of the service-speed display.

Tuesday, some of the sport's top guns took swings at lighting up those little scoreboards -- veteran American Andy Roddick (who reached 155 mph at the 2004 Davis Cup), up-and-coming Canadian Milos Raonic (155.3 this month in Montreal) and, among the women, Venus and Serena Williams (whose bests of 129- and 128-mph remain the fastest ever on the women's tour).

Even so, everyone in the sport agrees a serve's primary aim is not that velocity figure. "It's a fan-enhancement tool, not an official statistic," said Rallis Pappas, president of IDS Sports, which provides the technology to measure service speeds at the Grand Slam events.

Raonic, whose fastest serve Tuesday was 141 mph (equaled by Roddick), recalled "hitting 275 kilometers per hour [or 170 mph]" at the early-August Montreal tournament, "and that's ridiculous, because the gun wasn't accurate. So I don't look at this. I look at: Is the serve effective, doing the job?"

It was in 1989 that Pappas' company introduced its system at the Key Biscayne tournament and, in 1992, brought it to the U.S. Open. Though players don't always trust the numbers -- there are other setups employed at some lesser tournaments, and a Florida television station once reported police radar clocking a tree going 37 mph and a house going 28 -- Pappas said the IDS software guarantees an accuracy on plus-or-minus 1 to 2 mph.

Either way, players say they pay attention. "If somebody aces me, and I don't even see the ball," reigning U.S. Open champ Novak Djokovic said, "then I have a look at the speed gun just to know it's over 140."

Andy Murray uses the display to judge whether he is close to what should be his consistent speed, whether he is not hitting hard enough or "where it might be time to reel it in, because you'll probably miss if you're going too much harder," he said.

recommendedU.S. Open: Men's results

Players are perfectly aware that big numbers don't represent the actual speed of the ball after bouncing to the receiving player. IDS technicians "report the speed of the ball as soon as it leaves the racket," Pappas said, and they estimate that the ball loses roughly half that reported speed by the time it is struck by the returner.

"It is mostly for the fans," American veteran Mardy Fish said. "But I'd be lying to you if I didn't say I talk to my coach about how sometimes I can overserve, try to hit too hard and sort of get out of my comfort zone and my rhythm a little bit. If I'm getting to the low 130 range and missing quite a few, I'm overserving.

"You watch some like Roger [Federer] or Novak, even Andy Murray, I think it's no coincidence that they're at the top because they serve well, and they don't hit their serves 130 hardly ever."

When IDS first began to record speeds, Pappas said, "There were some players -- I won't name any names -- who would have us turn off the displays on court, even though the fans loved it."

recommendedU.S. Open: Women's results

Now, players are thoroughly accustomed to the speed clocks, which are available on all the Open's six TV-ready courts.

"I'm always paying attention," Serena Williams said. "Always, always. I'm trying to see if I can hit it harder."

And ring that bell.

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