There aren't any.
Yeah, you were preparing yourself to read something stupid, but it turns out you'll probably agree with the main points of this article. Don't worry, though. You'll still read something stupid, or I'm not doing my job.
Let's remember back when Tim Lincecum was really struggling. Really, really, really struggling. Bad enough for the Wall Street Journal to write stories with headlines like Yup, Tim Lincecum Is the Worst Pitcher Ever. Back then, it was okay to experiment. Everything was on fire, so it was worth seeing if the unmarked jug of fluid in the garage was water or kerosene. It's not like you were going to make things more on fire, so, hell, toss it on.
But there are times for experimentation. The playoffs are a time to play the best nine players available. The only way Sanchez is one of the best nine players available is if he makes Lincecum feel so comfortable, that it makes up for the drop in offensive and defensive production. When Sanchez plays, not only is his .282 on-base percentage in the lineup, but his less-than-stellar glove is behind the plate. He's improving, sure, but there's no question that Posey is the better receiver.
Posey isn't as good defensively at first as Brandon Belt, either, so there's a domino effect going on. When Sanchez catches, several aspects of the team get worse. The only way it makes sense to have Sanchez catch is a) if it gives Posey a rest, or b) if it makes Lincecum feel so comfortable that it makes the offensive and defensive downgrades worth it.
The numbers when the two catchers play with Lincecum.
Over a half-run difference in the ERA. That's meaningful! Except it really isn't. The average, OBP, and SLG are similar -- it's essentially the same guy, regardless of the ERA. Even if there were a huge gap, it probably wouldn't be meaningful. There are reasons why catcher's ERA isn't a widely used and well-respected stat.
You can't tell just by reading this, but I spent the last hour trying to make a fancy line graph. I failed. Spectacularly. But I was trying to update this chart:
Because it's not getting better. Lincecum threw a pitch in the strike zone 31.2 percent of the time on Tuesday night. If the goal of having Hector Sanchez catch Lincecum is to make him feel comfortable, it's not working. Last night, Lincecum looked as uncomfortable as he ever has.
That's Lincecum's problem -- he can't command his pitches. It's why he leaves them up where they can get hit. It's why they're thrown in spots that wouldn't even tempt Pablo Sandoval, which is what makes his walk rate horrific. That didn't change when Sanchez took over; Lincecum is walking even more batters with Sanchez catching than he did when Posey was catching.
The reason for the Lincecum/Posey separation is all speculation right now. Maybe Lincecum feels more comfortable with Sanchez. Maybe Posey used the turbo buttons on the NES Advantage during a game of Tecmo Bowl and won't admit it, so now Lincecum doesn't trust him. Maybe Bochy just doesn't want Posey diving around, trying to catch Lincecum. Maybe it's Posey who asked for the shift, but Bochy doesn't want to say that publicly. No idea.
But if Hector Sanchez is catching Tim Lincecum because it makes Lincecum feel comfortable, well, it's not working. Nice try. But it didn't work. He's still quite uncomfortable out there and wild as all heck.
Buster Posey catching, Brandon Belt starting at first, and Gregor Blanco starting in left is the best permutation of players the Giants can put out there. That should be the lineup throughout the postseason. It won't be during the games that Lincecum starts. I really wish I understood why.