Projecting Jake Peavy

For major league hurlers, calling Petco Park home is the pitching equivalent of winning an all-expenses paid trip to Disney Land. Bring us your homer-prone, your waiver-wire wanderers, your injury-plagued looking for a fresh start. Petco wishes to help you (sorry, Mark Prior: even the Happiest Pitching Place On Earth has its limitations).

Until July of 2009, right-hander Jake Peavy enjoyed the ambiance of Petco. Make no mistake: Peavy has been a very good starter in his own right. But, his home ballpark surely aided him.

Courtesy of ESPN’s park factor numbers, here’s how much Petco has depressed offense over the past three seasons:

Petco Park, 2007-2009:

Runs: 0.76
HR: 0.72
H: 0.85
2B: 0.73
3B: 0.92

(1.00 is neutral. Numbers under 1.00 indicate a park factor favoring pitchers, and numbers over 1.00 favor batters.)

Petco’s a massive pitcher’s park: that’s not breaking news. But the numbers still are staggering. Run-scoring is absolutely smothered in San Diego’s home ballpark.

Peavy was shipped to the White Sox in a deadline day shocker last July 31st. Here are the three-year park factors for his new home:

U.S. Cellular Field, 2007-2009:

Runs: 1.09
HR: 1.26
H: 0.99
2B: 0.89
3B: 0.61

There aren’t that many doubles and triples legged out in the Cell. That’s because those batters are too busy leisurely trotting around the bases, while Hawk Harrelson shrilly does his best to shatter every window in the greater Chicago area.

Over the past three seasons, Peavy has surrendered 0.44 home runs per nine innings at home, and 1.01 HR/9 on the road. The 28 year-old isn’t an extreme fly ball pitcher (41.8 GB%), but his groundball rate is a few ticks below the league average. Some of those flys that were innocuous outs at Petco are likely to carry over the fence at The Cell.

Let’s assume for a moment that Peavy’s strikeout and walk rates mirror his Bill James projection for 2010: 9.08 K/9 and 2.89 BB/9. But instead of his HR/9 average coming in well under 1.00, he gives up roughly one homer per nine frames. That’s about 24 dingers in his projected 215 innings.

That would make Peavy’s projected Fielding Independent ERA about 3.70.

Maybe you feel that James’ K/9 and BB/9 estimates aren’t quite right. Peavy did cruise once he returned to the mound with the Pale Hose. But those projected K and walk ratios are a dead ringer for his career averages in the N.L., in a pitcher’s haven.

There has been a disparity in the level of play between the A.L. and the N.L. Last offseason, Derek Carty of The Hardball Times examined pitchers switching leagues over the 2004-2008 seasons.

He found that those going from the N.L. to the A.L. received a “penalty.” As one might expect based on the A.L. possessing the DH and clearly playing a superior brand of baseball as of late, pitchers moving from the N.L. to the A.L. saw an across-the-board dip in performance. Pitchers going from the Senior Circuit to the Junior Circuit saw their K/9 decline by 0.57, and their BB/9 increase ever so slightly (+0.05).

Let’s apply those marks to Peavy’s projections. Now, his FIP is about 3.85.

None of this is to suggest that owners should shy away from Peavy. However, it is important to consider park and league effects when projecting a guy moving from a pitcher’s paradise in the N.L. to a homer-happy venue in the A.L. Also, his last two seasons have been curtailed by injury.

Peavy’s good. But if you’re looking for another ERA in the low-three’s, you’ll probably be disappointed.

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A recent graduate of Duquesne University, David Golebiewski is a contributing writer for Fangraphs, The Pittsburgh Sports Report and Baseball Analytics. His work for Inside Edge Scouting Services has appeared on and, and he was a fantasy baseball columnist for Rotoworld from 2009-2010. He recently contributed an article on Mike Stanton's slugging to The Hardball Times Annual 2012. Contact David at and check out his work at Journalist For Hire.

20 Responses to “Projecting Jake Peavy”

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  1. Matt B. says:

    This also shows how great Adrian Gonzalez (and Brian Giles) have been offensively in the past…

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  2. slash12 says:

    It will be interesting to see if Peavy makes some adjustments, that could change the results significantly as well. It would be to his benefit to try to induce more ground balls.

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  3. Scottwood says:

    Peavy’s xFIP from 2004-2008:

    2004: 3.56
    2005: 3.13
    2006: 3.82
    2007: 3.46
    2008: 3.92

    His xFIP was higher than his FIP in every single season and may be a better tool to look at going forward, considering the park effects, than FIP.

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    • JDSussman says:

      xFIP normalizes to league average HR rate. It would make sense that a pitcher (Peavy) pitching half his games in a HR killing park (Petco) would beat his xFIP.

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      • Scottwood says:

        Well, sure. But, he’s not going to be pitching in that park anymore and that advantage will be gone. Therefore, his previous xFIP’s might be of better use than his previous FIP.

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      • lookatthosetwins says:

        Yes, and this year, you’d expect him to perform worse than his xFIP, given half his games are now in the cell. Looking at those numbers, and giving a penalty for NL vs. AL and for pitching in the cell, you’d expect his xFIP in the 4.00 range, and FIP in the 4.15 or so range.

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  4. Paul says:

    Do we have something like standard deviations for park factors? Exactly crazy is PETCO?

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  5. MDS says:

    do not draft jake peavy.

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    • PhD Brian says:

      No draft him late mid to late. He is a valuable pitcher. I would take him around the 18th (or later) round in a 10 team league.

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      • CH says:

        I think he’s at least as good as AJ Burnett. Draft him wherever you would draft Burnett.

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      • MDS says:

        what is a ten team league? thats a foreign language to MDS
        i have no clue what his ADP will be, but he wont last til the 18th

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  6. jeffrey says:

    Great analysis David. I used some of those links to do the same kind of adjustment for Adrian Gonzalez. You can click the name link for more information, but if Agon played at Fenway instead of Petco last season, he would have probably posted a line close to a .324 BA/.435 OBP w/ 53.5 HR

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  7. Matt says:

    Take your White Sox hating bullshit somewhere else. Can’t wait to watch Peavy shut everybody up.

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  8. wolverin119 says:

    i’d take burnett first..but is a good comparison overal… white sox have shotty defense and burnett would prolly collect 2-3 more wins…

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  9. Mike says:

    Peavy looks quite a bit better than Burnett.

    The supreme crappiness of the AL central should probably be considered. You have to feel good about a guy throwing most of his games against KC, Detroit, Cleveland, and Minnesota.

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  10. Colin says:

    Peavy is a better than Burnett, BB/9.

    Peavy is still much better than the league average pitcher in the AL.

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  11. mnjoe says:

    Mike, don’t include Minnesota in that list, or even Detroit. Minnesota’s lineup is 10 times better than anything in the NL west or central (excepting St. Louis).

    And to Matt, oh how love white sox fans. Always so angry. This was an analytical look at a player and still thinks it’s white sox hate. Here’s white sox hate: if your dumb fans weren’t so busy hating a team across town that’s not even in your own league, maybe they could be a decent team. Have fun watching the corpse of Paul Konerko turn doubles into singles.

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