The Giants might not hit this year, or they might hit relatively well but still frustrate us all because of the park effects at home. More likely, though, their season will depend on their rotation. There are some question marks about this rotation. For example, they have seven could-be starters who might see action, with at least three could-be competent starters in the high minors, but don't confuse quality with quantity. The Giants could have both, but we know only of the quantity for sure.
Put it this way: The Giants' rotation is a road trip to Sacramento, and there's nothing but Pearl Jam on the stereo. Hey, it could be worse! And maybe you're meeting some really nice people and/or getting into adventures once you get there. It sure looks like a lot of average and okay from here, though, best case scenario. And maybe the Pearl Jam CD will skip and you'll have to bring in Matchbox 20 in relief.
Wait, no, it's a mix of CDs, and Bumgarner is Sticky Fingers, whereas the rest of the rotation are unmarked Stones CDs from the '70s, '80s, or '90s. Maybe Jake Peavy will be Goat's Head Soup, which would be great. Maybe he'll be Steel Wheels. I just hope Lincecum isn't a Bill Wyman solo album again. You could do this for hours.
The point: Bumgarner is good. He was worked hard, though, between the regular and postseason. How hard? Jeff Zimmerman at FanGraphs tallied up the number of pitches Bumgarner threw, which was 4,074. Since 1995, 30 different pitches threw more than 4,000 pitches in a calendar year, and Zimmerman decided to look at some of them, like ...
Russ Ortiz, 2002
Barry Zito, 2003
Tim Lincecum, 2010
And those guys were just fine forever and ever, case closed. Also, Ortiz has had more 20-win seasons over the last two decades than all Giants pitchers combined, so don't get so cocky.
(If you ever need to win an argument with someone about pitcher wins, I release the copyright on that last sentence.)
The conclusion Zimmerman reached, though, wasn't that everyone was doomed like Ortiz, Zito, and Lincecum, but that their collective careers predicted more than anything related to their strenuous season. That is, using the Marcel projections -- which use absolutely nothing but past stats, weighted toward recent seasons, and factoring in age -- did just fine predicting the performance of the pitchers who were worked hard. The system didn't account for workload, and it still worked. This is good news.
Part of this has to do with the self-selecting sample. Good, healthy pitchers are likelier to last an entire season/postseason and they're more likely to be healthy the next season because if they weren't, they probably wouldn't have lasted as long in the previous season. It's almost a tautology.
Some of the pitchers broke down and/or lost effectiveness. Some came back and reinvented themselves (Livan Hernandez), and others were absolute specimens who shouldn't be compared to anybody (Randy Johnson). All of the bad things could be related to the workload, but don't forget that one of the most harmful things a pitcher can do is pitch at all. Maybe that's a list of pitchers who eventually got burned for being pitchers, like almost all the rest of them.
For the next season, though, everything went as expected. So if you're quietly freaking out over Bumgarner's workload, that's your prerogative. You can do what you want to do. The evidence doesn't support anything like that, though. I like this evidence.
Still, it's hard to dismiss. Here's a little-known fact about the 2014 World Series: Bumgarner actually came out of the bullpen in one of the games, and he did it on two day's rest. That seems like it would be taxing on the arm. You have numbers up there, all regressed and shiny, but there's still that anecdotal part of your brain that releases endorphins. You can't help but wonder if all that work is going to catch up to him. You can't help but wonder because of the sweet, illogical endorphins. Your brain is counting on those.
So vote in another poll. On a scale of Prior to Buehrle, how worried are you about Madison Bumgarner? I'll go with kind of worried and not thinking about it, even if my heart wants the first one. The stats and history are on our side, at least. We'll take it.