Everybody's been crowning Jimmie Johnson with his fourth straight Sprint Cup, and with good reason -- the guy's an overwhelming favorite to dominate the field. But "overwhelming" doesn't mean "certain," so let's take a look at how he could possibly lose this thing.

First off, it'll take a massive charge by one of the four guys following him most closely -- Mark Martin (118 points back), Jeff Gordon (150 points back), Tony Stewart (192 points back) or Juan Pablo Montoya (200 points back). Second, Jimmie's got to stop winning races, or this thing's completely over. Third, there are only a certain number of points that each driver can gain on Johnson each week -- the maximum possible is 161 (195 points for winning and leading the most laps, assuming Johnson finishes dead last and gets 34 points; see a full breakdown of how points work right here).

So let's break this down, giving assumptions on how well each guy would have to run if Johnson averaged certain places over the course of the last four races. Over the last four races, we estimate that ...

If Jimmie averages a third-place finish:
-Martin would have to win all four races and lead the most laps in each.
-Gordon, Stewart and Montoya have no chance.

If Jimmie averages a fifth-place finish:
-Martin would have to win all four races, though he wouldn't need to lead the most laps.
-Gordon, Stewart and Montoya have no chance.

If Jimmie averages a tenth-place finish:
-Martin would have to average just below a third-place finish in every race.
-Gordon would have to win one race and place no lower than second in the other three.
-Stewart would have to win all four races, or place second in one if he leads in the most laps in another.
-Montoya would have to average 185 points -- the exact total for winning all four races.

If Jimmie averages a 15th-place finish:
-Martin would have to average a sixth-place finish.
-Gordon would have to average slightly better than a fifth-place finish.
-Stewart and Montoya would have to average a second-place finish.

So it's not impossible, but it's going to be extremely tough, as of right now, for anybody to catch Jimmie. Still, there is precedent, as recently as last year -- Carl Edwards won three of the final four races, and Kyle Busch posted back-of-the-field finishes in the first two.

Rooting for Johnson to fail is seriously bad karma, but should he have difficulties at Talladega, the door opens considerably wider. We'll check in next week at this time and see where we stand.

Related: Carl Edwards, Mark Martin, Jeff Gordon, Kyle Busch, Juan Pablo Montoya, Jimmie Johnson, Tony Stewart