I think ultimately the question is: does the versatility of having Vogelsong as a longman/caddy for Timmy or Zito (in role he's been in before) outweigh the hypothetical increased value of Vogelsong starting Game 4 and Zito as a questionable reliever? I'm assuming Timmy is assured Game 3, and I can't really argue that Zito is a better starting pitcher for the Giants than Vogelsong -- there is just something to be said for having a pitcher like Ryan (fearless, throwing low 90s, etc) as a bullpen weapon. You have to consider construction of the roster and each player's potential role, in addition to just comparing them as baseball players.

I think it may come down to two key results: How Timmy pitches Game 3, and what the score of the series is at Game 4. If it's Giants up 2-1 I say go Zito. If it's Reds up 2-1 you have to pitch Vogelsong (assuming he didn't pitch significantly previously). Let's just keep our fingers crossed that it's a sweep :)

I think the tenor of this post ignores the fact that Zito has actually been a pretty decent pitcher for the past few years.  He was a solid middle-to-back of the rotation guy in both 2009 & 2010.  Yes, his SO/BB/HR "building blocks" leave something to be desired, but Zito is better than most at inducing weak contact - along with Cain, he has consistently outperformed the rest of the league in the proportion of weak fly balls he gives up relative to total fly balls.  This is reflected, amongst other things, in his perfectly respectable ERA in the low fours in 2009, 2010, and 2012.  2011 was obviously a year in which he had some backsliding, but he was hurt for much of the year and in-and-out of the rotation and I think it's fair to say based on his performance this year that he is back to 2009/2010 levels, or better.The main difference between this year, where there is a pretty compelling case to start Zito in the post-season, versus 2010, when he was clearly the weakest of the 5 starters, is that Zito is hot right now.  In 2010, Zito's overall year was decent, but he was also the only member of the rotation that never really recovered from the August doldrums and posted a mediocre September - our other four guys were lights out in Septemeber, so the post-season rotation was obvious.  In contrast, this year Zito has been solid down the stretch, with four quality starts in his last five outings (and the fifth would have been a QS as well, had he not been pulled after 5 2/3).  His "basic building blocks" have been solid during that period as well - 6.8 K/9, 2.6 BB/9, 0.3 HR/9.Bottom line, I personally trust Zito more than Vogey or Lincecum right now.  As crazy as it seems, Lincecum is probably the weakest link in the rotation.  With that said, I'm pretty sure Boch will go with Lincecum game 3 and Zito game 4.  Vogey can probably help the team as a long man more than Lincecum or Zito would and I guarantee Boch will be quick with the early hook if called for in the Lincecum and Zito starts in particular.I was encouraged by the fact that Posey was supposed to start last night's game before the back spasm issue.  I hope we'll stick with Posey catching Zito in the postseason - Zito has always been a guy who is more willing than anyone else on the staff to take responsibility for shaking guys off, so the adjustment to a different catcher should be less acute than with Lincecum, who I think will keep Sanchez as his catcher.

I'd set the lineup Cain-Zito-Bum-Vogey-Cain.  Zito may be a "below average pitcher", but even players meeting that criteria can still produce if placed in the right situation.  I'd feel much better about Zito starting a home playoff game rather than being forced into a game 4 start in the GAB, where he'd have no chance of keeping the ball in the park.

Lincecum 10-15, 5.18 ERA   23 Hrs allowed, most of his careerZito 15-8, 4.15 ERA   20 Hrs allowed, much less than when he was with Oakland.It's a matter of who's pitching better right now, and as much as I love to watch Timmy, Zito deserves to start. 

Game 3's starter will be Tim Zitosong.

I completely agree that Zito's improved numbers this year are as much about additional run support as anything else, however I am not sure that I agree that either Lincecum or Vogelsong is throwing the ball better at the moment.  I don't pretend to know what Bochy will do (although I would strongly guess that Timmy will be starting), however for mine Cain and Bumgarner should be the only two with no doubts about their place in the postseason rotation.And if we are making the argument that Zito is just doing what he has always done in a Giants uniform, then it's probably not a bad time to mention his record against the Braves ...

Another thing to consider: If Vogelsong is starting instead of Zito, Bochy can't be tempted to start Hector Sanchez at catcher for that game.  For me, that makes it an easy decision.  No need to even get into the fact that Vogelsong is the better pitcher.