DeWitt Clinton’s men’s tennis team roared through its regular season schedule this year, finishing without a single blemish on its record.

The team has managed its incredible run on the backs of savvy play by veteran juniors and seniors, good coaching, and help from an unexpected source – a retired businessman who lives over an hour from the Bronx.

Last year, while retired businessman Michael Schwartz was cleaning out his home in New Jersey, he came upon his cache of 20 tennis rackets. No longer able to use them due to operations stemming from diabetes, Schwartz contacted high schools near him to see if they could use his equipment.

When the schools in Schwartz’s area told him they had no need for the rackets, his wife suggested he try an inner-city school, and he found himself contacting the tennis coach at his alma mater, DeWitt Clinton.

Schwartz says that when he contacted Clinton coach David McDonough, he “jumped at the chance” to get the rackets for his team. A few days later, when the two met for the racket exchange, McDonough offered Schwartz the role of assistant coach of the team. “I figured the guys could really benefit from his experience,” says McDonough.

After playing tennis for DeWitt Clinton and graduating in 1964, Schwartz went to the University of Alabama on combined tennis and ROTC scholarships. Schwartz ultimately went on to become vice president for clothing manufacturer Phillips Van Heusen, and then later, general manager of a Porsche dealership in Long Branch, New Jersey.

The most important lesson that Schwartz says he has been able to bring to Clinton’s players is what he calls the “85 percent rule.” Schwartz explains, “You don’t have to worry about a winning shot, just keep the ball in play. If you hit the ball back over the net 85 percent of the time, you’ll win the point by forcing your opponent to make an error.”

A glance at the team’s statistics over the course of the season reveals that they’ve taken this rule to heart.

In addition to on the court lessons, Schwartz has sought to bring a sense of tradition to the team. At a team meeting before their final game, Schwartz and McDonough presented some of the players with varsity letter sweatshirts. The coaches were unsure how the team would respond when the letters were only given to the team’s captain, and players who had competed in at least five matches.

“The kids who didn’t get letters weren’t envious,” McDonough said. “They understood right away that it was something to work for and earn.”