NASCAR is about to start finding out whether its offseason changes will pay off on tracks like Las Vegas Motor Speedway. NASCAR worked tirelessly behind the scenes last year to improve its on-track product, particularly at 1.5-mile speedways that had turned into glorified parades. While fans watch defending champion Matt Kenseth and early points leader Dale Earnhardt Jr., everybody on the north end of The Strip is eager to see if passing is any easier and if the racing is any better Sunday in Vegas. Gene Stefanyshyn, NASCAR's vice president of innovation and racing development, warned that one show won't be a true barometer of the changes made to the rules package. More...