There's no single, universal, linear path that a driver follows from grassroots racing to NASCAR stardom. Plenty of drivers hone their skills on their local short tracks in late models, progressing their way up the ladder before finally landing a gig in the big time. For years, that was the way things worked.
But in recent years, as NASCAR has established a global presence, more and more Sprint Cup drivers have come from different backgrounds. Many of them have reached the highest level of other disciplines, winning major races and championships before switching over to stock cars.
Granted, those stellar pedigrees elsewhere may secure NASCAR employment, but that doesn't guarantee success. Some of these drivers have pulled the career switch off better than others, but these 10 have established themselves as some of the most versatile in the sport:
The former 24 Hours of Daytona winner and longtime CART competitor came to NASCAR with Geico sponsorship in 2009, running a limited Sprint Cup schedule before transitioning to Camping World Trucks, where he spent the 2011 season.
Last year, Papis finished 18th in Truck points with two top-10 finishes. He's also scored nine wins combined in sports cars and CART.
Hornish has been one of the least successful drivers to transition from open-wheel racing to stock-car racing and stick. Granted, expectations were unreasonably high in the Hornish camp; after winning his third Indy Racing League title with Team Penske in 2006, owner Roger Penske attempted to switch Hornish directly to the Cup level.
It didn't pan out, though Hornish has improved in limited Nationwide runs and won his first race in that series at Phoenix in November.
Last season, Busch made news by entering the NHRA Gatornationals in the Pro Stock class, advancing to elimination rounds. But the inaugural Chase for the Cup champion has tried his hand at more than just drag racing; in February 2003, Team Rahal brought Busch to Sebring International Raceway for a CART test.
Mears, nephew of four-time Indianapolis 500 winner Rick Mears, started as an open-wheel driver who briefly replaced Alex Zanardi after his career-altering injuries in 2001. From there, Mears moved to what was then called the Busch Series, joining Chip Ganassi's team in Cup in 2003.
He's been there ever since, scoring one victory in the 2007 Coca-Cola 600, and now drives for Germain Racing there.
Franchitti's stock-car experiment will probably be looked upon as a failure, but it's not a huge knock against the man who has won the last four IndyCar championships in which he competed. Franchitti won his class in the 2007 12 Hours of Sebring while driving for Andretti Green Racing, and took the 2008 24 Hours of Daytona with Chip Ganassi Racing teammates Juan Montoya, Scott Pruett and Memo Rojas.
Allmendinger just landed a deal with Penske Racing to replace Kurt Busch in the No. 22 Sprint Cup car, where he'll attempt to take his first career NASCAR win. But before switching to stock cars, Allmendinger took five wins in three seasons competing in the Champ Car World Series.
Allmendinger also competes in the 24 Hours of Daytona frequently for Michael Shank Racing; the 'Dinger is also a part owner in Shank's new IndyCar operation.
Ambrose remains the only driver to ever win a race in each of his V8 Supercars seasons, spanning from 2001 to 2005. The 2003 and 2004 champion of that series moved to NASCAR in 2006 and hasn't looked back since, frequently dominating road-course races and collecting five career NASCAR wins.
His first Sprint Cup triumph came last season at Watkins Glen.
You name it, Robby Gordon's raced it (and probably won it). Currently competing in Sprint Cup as an owner-driver and the Dakar Rally in South America, Gordon has won numerous off-road racing championships, class wins in both the 24 Hours of Daytona and 12 Hours of Sebring, and a handful of CART and NASCAR victories.
Gordon hasn't competed in the Indianapolis 500 since 2004, focusing on his NASCAR and off-road exploits, but nearly won the race in 1999.
Three Sprint Cups, an Indy Racing League title, numerous USAC and go-kart accolades, and wins in some of the biggest races in America have earned the man they call "Smoke" the respect and admiration of millions.
Through it all, Stewart has forged a relationship with his archetypal mentor, the great A.J. Foyt, another driver to win in just about anything on four wheels in America.
If Tony Stewart is the modern A.J. Foyt, Juan Montoya is the modern Mario Andretti. Montoya has won the Indianapolis 500, Monaco Grand Prix, CART championship and 24 Hours of Daytona; all but Monaco he accomplished on his first try.
Montoya has finished fourth or better in all three Indianapolis events, nearly winning the Brickyard 400 on multiple occasions, and scoring points twice in the United States Grand Prix. Montoya finished third in the Formula One World Championship twice, in 2002 and 2003.