New York ? NBA players have complained all month that the league’s new synthetic ball feels and performs differently from the old leather one.

According to results of a study requested by Dallas Mavericks owner Mark Cuban, they may be right.

Physicists at the University of Texas-Arlington released results of preliminary tests they say prove the microfiber composite ball doesn’t behave like the old leather ball. A number of players have griped about its grip and unpredictable bounce since training camps opened.

Cuban contacted Dr. James L. Horwitz, chairman of UT-Arlington’s physics department, to test both balls – though the owner says he has no intention of doing anything with the results.

“Nothing,” he told the Associated Press in an e-mail. “Just try to support the commissioner and the league to the fullest of my ability with the data.”

According to the results released Sunday, the ball bounces 5 to 8 percent lower than typical leather balls when dropped from four feet. It also found the new ball bounces 30 percent more erratically.

Commissioner David Stern dismissed that complaint last week and said the NBA is staying with the new ball. Cuban said the league should do the same in his Internet blog.

Dan Touhey, vice president of marketing for Spalding, said the difference in bounce could be because of the surface it was bounced on, or more likely because of the age of the balls. An old leather ball will bounce more than a new one, as well as a new synthetic ball.

He said the leather ball tested had to be an older one, because Spalding hasn’t shipped new leather balls to teams since August 2005.

“That ball is probably out of the NBA’s spec, and if it’s not, it has a greater likelihood of being so,” Touhey said. “There was a lot of wear and tear on that ball, no question.”

**FILE** The new NBA basketball sits on the court during a timeout as the Denver Nuggets play the Los Angeles Clippers during the first half in of an NBA preseason game in this Oct. 27, 2006, file photo in Los Angeles. (AP Photo/Jeff Lewis, File)

The other finding of the study directly contrasts with what the NBA and Spalding have said about the feel of the ball when it is wet.

The league has stressed that one of the advantages of the composite material is it’s easier to grip when it starts to get damp. But the researchers found it’s less absorbent than leather, causing it to be more slippery when moist.

But Touhey said one of the strengths of the new ball is it prevents the absorption of water, which changes the weight of the ball as the game goes on.

“We felt pretty strongly that our tests and the way we conducted them were giving us accurate readings,” he said. “One thing we don’t know is how they wet the material. That’s an unknown for us. We tried to replicate the rate of perspiration. We did not dunk it in a basin of water. We tried to replicate game situations throughout all these tests.”

The study recommends frequently drying or changing the balls during the game. An NBA spokesman said it is up to the officials’ discretion if the ball should be changed during play.

Also, the physicists recommended inflating the ball to 14.5 pounds per square inch, rather than the regulation 8.5 psi, to address the problem of its lack of bounce.

But no matter what, the ball figures to remain a headache for the league. Players have offered little support for it, and some of the harshest criticism came from Shaquille O’Neal, whose Miami Heat play the first game of the NBA season tonight.

At a lunch Monday with TNT studio partners Ernie Johnson and Kenny Smith, Charles Barkley added his concerns about the ball.

“The one thing I hate about the ball, it always feels new,” he said. “And if you ask Kenny, when we played, we always wanted an old, used ball.”

Smith, who was part of the press conference in June when the ball was introduced, said complaints are natural any time there is a change.

“It has a different texture,” he said. “I would say if you score 40 with it, you’ll probably like it a little bit more. Out of all the things in the game that you can change, the one thing that does affect the game is the ball.”

The UTA researchers plan further tests to continue evaluating the ball.