How Good Is The San Francisco Giants Pitching Staff?

Quick Note: While xFIP is my favorite popularized metric to predict future (luck-neutral) ERA, I have become more enamored with xFIP 2.0 lately, which uses HR/OF_FB% (outfield flyball%) to calculate the xFIP metric. However, calculating a player's xFIP 2.0 (or maybe just xxFIP) would take too much time right now (as it is not pre-calculated) and I have a law review to get back to writing. Therefore, for the quick and dirty purposes of this post, I shall use xFIP (as I did in the preseason) as the baseline for my analysis.

The 2010 SF Giants are currently the best defensive team in baseball. They have accumulated a team Fielding Runs Above Replacement (FRAR) of +18.0, meaning their defense alone has won them an additional ~1.8 games compared to the mythical "league average team." At this rate, Giants gloves are preventing +0.38 runs per inning. If all stays constant, what does this say about the 2010 Giants pitching staff going forward??

Right now, the Giants are fourth in baseball with a team ERA of 3.25 and are sporting the highest team K/9 mark (8.00, slightly ahead of the Cubs' 7.98 mark) in the league. The starting five -- Tim Lincecum, Matt Cain, Jonathan Sanchez, Barry Zito and Todd Wellemeyer -- have respective ERAs of 3.14, 2.36, 2.90, 2.78, 5.03. At the behest of a friend, who claimed that Zito was awesome, I took a look at what would happen if we adjusted each starter's peripherals based on park/defensive metrics. The results are interesting.

According to Baseball-Reference's 3-year park factor data, AT&T Park has inflated total run scoring by ~4%. Using this index, the Giants' FRAR/Inning rate and xFIP data, we can project each starter's prospects for the rest of the season, boldly assuming all (such as K/9, BB/9, GB%, FRAR/Inning) stats remain constant. Adjust mentally based on where you think each player will improve/regress as the season progresses.

All of the above produced the following chart:


Cain has obviously outpitched his peripherals so far this season with a career low K/9 rate. If Cain can regain his strikeout talents going forward, I'd take the under on his ERA projection.

Other than Cain, the rest of those numbers seem about right to me. What do you think?