Kershaw's thrown nearly 400 more innings than Bumgarner, thanks to his nearly two-year head start. Plus, the biggest feather in Kershaw's cap is the 2011 Cy Young award, which the Dodgers ace took home after a brilliant 2011 campaign.
But if you start to look at the two stud lefties, and compare their accomplishments relative to age and experience, the discussion gets pretty interesting.
For example, this season, Bumgarner has a narrow edge over Kershaw in ERA (2.83 to 2.87), WHIP (0.99 to 1.00) and in the win column (14 to 11). Those numbers are all strikingly close, and the critical reader would be right to point out that they're too similar to really favor Bumgarner in a meaningful way.
But when you consider that Bumgarner is nearly a year-and-a-half younger than Kershaw, the fact that the Giants' ace has outpitched his Dodgers counterpart this season—however slightly—does take on some real significance. Despite Kershaw's advantage in the age and experience departments, Bumgarner has narrowly nosed past him.
There's also reason to believe Bumgarner will continue to improve, as he's already an expert in the one area where Kershaw has historically struggled. Though he's improved his command significantly over the last few seasons, Kershaw's control isn't as good as Bumgarner's.
This year, Kershaw's strikeout-to-walk ratio is 4.17-to-1. Bumgarner, though, is at 5-to-1. For their careers, the difference favors Bumgarner even more strongly. Kershaw's lifetime ratio is just 2.88-to-1, while Bumgarner's is 4.18-to-1. Because control is usually the last thing young pitchers perfect, Bumgarner's early mastery in that department bodes very well for his future development.
Going forward, Bumgarner's got another advantage over Kershaw, but not necessarily in the skill department. We're talking about value.
The Giants bought out Bumgarner's arbitration years by signing him to a six-year, $36 million contract in April of this year (the deal could include a couple more seasons if the options are exercised). If he keeps up his current level of performance, that will be an epic bargain for the Giants, who'll retain his services as he nears his 30s.
Kershaw, on the other hand, is only signed up with the Dodgers for two more years, for just $19 million. And while that's a phenomenal deal for a pitcher as good as Kershaw, it means he's going to hit free agency in his mid-20s. Wherever he signs, you can expect his contract to approach—and probably exceed—the record deal between the New York Yankees and CC Sabathia.
Strictly from a value standpoint, I'd much rather have Bumgarner than Kershaw.
The comparison between Kershaw and Bumgarner is an extremely close one. If you favor known commodities, Kershaw's longer track record of success is probably appealing. But if you look at Bumgarner's accomplishments so far, including the fact that he might well be slightly better than Kershaw right now, he starts to look pretty good, too. And, you can't forget that Bumgarner is younger and still trending upward.
Ultimately, any team would be ecstatic to have either ace. But as of this moment, Bumgarner might be the better option for the future.