NEW YORK – Jim Courier can find only one possible flaw with instant replay in baseball, and it's purely personal.

“I'm going to miss seeing Lou Piniella throw his cap,” the former tennis star said this week at the U.S. Open. “I used to love when Sweet Lou would toss those bases.”

A huge Cincinnati Reds fan, Courier won four Grand Slam championships. Major League Baseball starts replay Thursday and he's sure the chance to review grand slams – and other home runs – will be a hit.

“It's made a fluid entry and quickly become part of the tennis landscape. There has not been one iota of drawback. Not from players, tournament officials or fans,” he said. “I think baseball will like it. Anything to help get the calls right.”

The U.S. Open was the first major tournament to try replay in 2006, giving players a chance to challenge line calls. Wimbledon and the Australian Open also employ it now; the French Open doesn't, saying balls leave visible marks in the clay surface.

“It has worked better than anyone expected,” U.S. Open tournament referee Brian Earley said.

Through Tuesday night, slightly more than 30 percent of disputed calls had been reversed during three years at Flushing Meadows. There had been more than 550 challenges – over two per match, on average.

Top-seeded Rafael Nadal won a tiebreaker against Bjorn Phau on an overturned call Monday. Andy Roddick frequently contests calls at the U.S. Open but is rarely right, going just 4-for-17.

The Hawk-Eye technology has definitely helped limit disputes. Earley imagines the same thing will happen in baseball.

“I've heard people say that tennis set the standard for the introduction of replay. Not just the quality, but how it was done. We didn't rush it, we put it through its paces,” he said. “We made sure the players had confidence in it. We knew that if we didn't do that and then it failed, it would be years before we could try it again.”

“You can make all the right calls you want, but if the players don't have confidence in it, it's a recipe for disaster,” he said. “I think it will work great in baseball. It will add to the enjoyment of the spectators.”

Vince Spadea was born in Chicago, but admits he's not much of a baseball fan. Still, he's in favor of another sport adding replay.

“Football does it. Basketball, too. Why not in baseball? The tradition?” he said after his first-round loss Tuesday to former U.S. Open champion Marat Safin.

“I like it. It certainly helped me today. I was right a few times,” he said. “It'll be good for baseball. The world changes, things evolve. That's the way things go.”