The bubble: How easy is it to pop and burst through?

If past performance is any indication, there's a better than 50-50 chance that either Brian Vickers or Kyle Busch will find themselves in the Chase for the Sprint Cup after Saturday night's race at Richmond, but the odds are against both of them making it in.

And it would take an unusual circumstance, the likes of which has happened only twice in this decade, for someone other than Matt Kenseth to find themselves on the outside looking in.

Looking at the Richmond results for a nine-year period beginning in 2000, on five occasions a driver outside of the top 12 would have leapfrogged his way into a Chase position, had the current format been in place. In fact, between 2003 -- the year before the Chase format was implemented -- and 2006, the driver in 12th position was either knocked out or, in the case of Jeff Gordon, tied for the final spot.

Of course, it's purely conjecture in some respects, because teams were racing under the conventions of the day and not using contemporary strategies to make the Chase field, especially before the field was expanded from 10 to 12 in 2007. But it's possible to extrapolate with a fair amount of certainty how the 12 spots would have been determined.

The past two seasons have been the most stable for drivers hoping to lock themselves into the top 12. In 2007, Kevin Harvick had a nearly insurmountable 128-point lead over Dale Earnhardt Jr. Last season, David Ragan and Kasey Kahne were both within 50 points of Clint Bowyer, but Ragan finished 32nd at Richmond and Kahne 19th.

But had there been a 12-man Chase format in place starting in 2003, things might have turned out very different under the lights at the Richmond Fairgrounds. If there's a scenario that Juan Montoya, Ryan Newman, Mark Martin and Greg Biffle would like to avoid Saturday night, it would be repeats of 2003 and 2006. (Continued)