At Lone Star Park, it's time to drive up and place your bets--all without leaving your car.

The Grand Prairie, Tex., racetrack is offering drive-through wagering starting this morning for bettors in a hurry.

"We're trying something new to make it more convenient for our avid horse players," Corey Johnsen, vice president and general manager of Lone Star Park, told the Fort Worth Star-Telegram.

Lone Star is the second thoroughbred track in the country to institute drive-through betting windows.

Johnsen said the plan followed favorable response to drive-through windows at Keeneland, a thoroughbred track in Lexington, Ky.

The Texas track's program has been in development for about a month.

Drive-through windows will provide convenience for bettors but perhaps not as much for the serious horse players, said Bill Thompson, professor of public administration and a gaming expert at Nevada-Las Vegas.

"The serious gamblers, the real gamblers, are going to want to see them on television or live," he said. "It will make it easier for the bookies to get their money in." . . .

Silverbulletday, seventh in the Belmont Stakes June 5 in her debut against males, will return to competition against 3-year-old fillies Saturday at Monmouth Park--and they're not exactly rushing to welcome her back. Mike Pegram's winner of 11 of 13 starts drew only four rivals for the 1 1/16-mile Monmouth Breeders' Cup Oaks.

Auto Racing

Martin to Race Sunday

Mark Martin underwent surgery Wednesday to repair a broken tibia plateau in his left knee. The NASCAR Winston Cup driver was hurt in an accident last Friday at Daytona International Speedway.

Chuck Kollmer performed arthroscopic surgery in New Smyrna Beach, Fla., inserting a screw to hold the tibia in place. Martin will continue to wear a leg brace, which will allow him to drive in Sunday's race at New Hampshire International Speedway.

"Dr. Kollmer assured me that I will be able to drive this weekend in New Hampshire," Martin said. "I'll go back to see him Monday after the race to evaluate how long I should wear the brace. Once I get this taken care of, I should be much better since my wrist and ribs are already feeling better."

The crash occurred when a tire was cut and the rapid loss of air sent Martin's car slamming into the wall. He drove in Saturday night's race and finished 17th despite a fractured bone in his left wrist, sore ribs and the knee injury.

Officials for Roush Racing said Martin intends to drive the entire race on Sunday, but that NASCAR Busch Series driver Matt Kenseth will be standing by should a substitute be needed.

Basketball

Draftee Loses Temper

Dallas Mavericks draftee Leon Smith stormed out of his first formal NBA workout Tuesday after refusing a coach's order to run an extra set of sprints and flinging his practice jersey to the floor before stunned teammates and spectators.

Smith, the Mavericks' first-round draft pick, apologized later that day to the team after a closed-door session with assistant coach Donn Nelson and father Don, the Mavericks' coach and general manager.

The outburst began near the end of the afternoon workout at the Mavericks' Baylor-Landry Center practice facility. Smith, 18, had been told to complete the additional sprints but then asked Don Nelson, "Why don't you run it?"

When Nelson asked Smith to repeat the comment, the draftee complied.

"That's two more for you, Leon," Nelson replied.

But Smith left for the Mavericks' locker room instead of running either set.

"I sat down with him and we talked about it," the elder Nelson said. "We're going to put it behind us." . . .

Prudential Insurance Co. of America offered to arrange up to $170 million in financing for a proposed arena to be built by the New Jersey Nets in Newark, the company said. Officials of the NBA team said the proposal by the Newark-based insurer will help them attract more private investors for an arena with a projected cost of $290 million. Prudential said it wants to see whether the Nets can sell enough tickets and luxury boxes in Newark before committing to the project. The Nets have projected the new arena to open by 2003.

Locally

Job Fair

D.C. United and Clark Construction will host a Summer Job Expo on Saturday at RFK Stadium from 5 p.m. to 7:30 p.m., prior to D.C. United's match against the Colorado Rapids. The job fair, at which area companies and organizations will have booths, will be located adjacent to gate F, near parking lot No. 4. Companies interested in participating can call Skip Kruger at D.C. United at 703-397-5444. The Washington Post is among the corporate sponsors.

CAPTION: Pat Jones of Lexington, Ky., places a bet at the drive-through at Keeneland. Starting today, bettors at Lone Star Park will be able to do the same.