Mile Fly City?

Recently, one of our readers, Simon, noted that the Rockies might be targeting fly-ball pitchers with the recent additions of Guillermo Moscoso, Jamie Moyer and Jeremy Guthrie. I decided to examine if going after fly-ball pitchers was a practical method for limiting runs at Coors Field.

In an ideal world, the Rockies would love to have all extreme sinker-ball pitchers. The Rockies GM, Dan O’Dowd, stated this stance recently on Clubhouse Confidential.

In an ideal world, every single guy in Colorado would be a heavy sinker ball guy who would have a tremendous ground ball to fly ball ratio.

It is not an ideal world and he knows it. He goes on further to state:

Unfortunately not all of our decisions are made in an ideal world. When we balance fly ball rates, we really try to balance soft and hard.

To see if using extreme fly-ball pitchers would be an advantage for the Rockies, I calculated, using Retrosheet data, the batted-ball data for all hitters at Colorado and the rest of the league. I looked at the numbers from 2002 (the first year the humidor was used at Colorado) to 2010 (the last year I have imported the Retrosheet files). Here is the data:

Ground Balls AB BABIP AVG SLG ISO HR% % of Batted Balls
COL 17543 0.214 0.214 0.234 0.021 0.0% 46.3%
League 489744 0.226 0.226 0.246 0.020 0.0% 46.3%
Fly Balls
COL 11919 0.156 0.253 0.706 0.453 11.5% 31.5%
League 363535 0.139 0.221 0.598 0.376 9.6% 34.3%
Line Drives
COL 8433 0.726 0.731 1.006 0.274 1.8% 22.3%
League 205104 0.705 0.712 0.979 0.267 2.3% 19.4%

First off, it is obvious that ground balls are the best end result for a pitcher in Colorado, or anywhere else. The advantage of having a fly-ball pitcher is not so apparent. In Colorado, hitters will have a higher AVG (by about 30 points) and ISO (by about 80 points) on fly balls vice elsewhere. These increases are more than those seen in AVG (increase of about 20 points) and ISO (increase by fewer than 10 points) by line drives in Colorado when compared to the rest of the league. Having a fly ball hit off a pitcher in Colorado is not an ideal outcome.

Colorado states that it is actually looking for pitchers who induce weak fly balls, so I collected a few stats for the pitchers they added this offseason. First, I got the pitcher’s career batted-ball data. Besides the batted ball data, I got the number of hard hit fly balls (> 250 ft) and soft hit (80 ft to 250 ft). I used the batted-ball distances from MLB’s Gameday data (same data that Pitch FX data come from). Ideally, Hit FX data would be used, but it is not available to the general public. Here is the data for the Colorado pitchers. I included the MLB average values and the numbers for Jhoulys Chacin, a ground-ball pitcher for Colorado, and Matt Cain, the poster child for weak contact on fly balls:

Name LD% GB% FB% IFFB% HR/FB 80ft-250ft >250ft Weak FB%
Jeremy Guthrie 18.3% 40.6% 41.0% 10.3% 10.2% 429 623 40.8%
Guillermo Moscoso 17.7% 26.8% 55.5% 12.4% 6.2% 81 89 47.6%
Josh Outman 16.6% 39.6% 43.9% 7.3% 4.9% 62 88 41.3%
Jamie Moyer 14.7% 44.1% 41.1% 8.6% 13.2% 301 392 43.4%
Tyler Chatwood 22.0% 47.0% 30.9% 7.5% 9.6% 58 82 41.4%
Jhoulys Chacin 17.7% 52.4% 29.9% 9.7% 10.7% 71 160 30.7%
Matt Cain 18.5% 37.2% 44.2% 12.6% 6.5% 477 629 43.1%
ALL 18.2% 44.3% 37.5% 9.3% 82700 114393 42.0%

Of the pitchers who Colorado picked up, Moscoso looks to be the ideal model for weakly hit fly balls, with 12.4% IFFB and HR/FB of 6.2% — a weak-hit fly ball rate over 5 points more than the league average. Matt Cain and him have similar batted ball profiles. The knack for inducing weak contact can be seen in the pair’s ability to have have a better career ERA than their FIP, xFIP and SIERA

Moscoso, 3.47, 4.22, 5.05, 4.96
Cain, 3.35, 3.69, 4.26, 4.20

Of the other pitchers brought in this offseason, Jamie Moyer is the closest to fitting the model of a pitcher who induces weak-hit fly balls. His weak hit % is similar to Matt Cain. Both are near 43%. Moyer has seen his ERA outperform his ERA estimators over his career, but not to the level of Moscoso and Cain:

Moyer, 4.24, 4.46, 4.65, 4.66

Jeremy Guthrie and Josh Outman both have above average fly ball rates (41% and 44% vs 38%). Their problem is that they seem to allow long hit fly balls at an above average rate (both at 41% vs 42% for league). Even though they both allow an above average number of hard hit fly balls, they have seen their ERA stay below the other ERA estimators:

Guthrie, 4.19, 4.68, 4.61, 4.50
Outman, 3.75, 4.01, 4.53, 4.51

Also the Rockies traded for Tyler Chatwood. Chatwood will join Jhoulys Chacin as one of the sinker ball pitchers vying for a spot in the rotation. The Rockies acquired two other pitchers, Alex White and Drew Pomeranz, as part of the trade that sent Ubaldo Jimenez to Cleveland. The pair are reported to be ground-ball pitchers. Currently, they look to have little chance of making the initial MLB pitching staff.

Dan O’Dowd was correct that they Rockies did bring in a couple of weak fly-ball pitchers in Moscoso and Moyer. Guthrie and Outman don’t seem to induce weak-hit fly balls, but have been able to outperform their ERA estimators in the past. While it is not ideal to have fly-ball pitchers, especially in Colorado, the Rockies have acquired some pitchers at the extreme end of the fly-ball spectrum. These pitchers allow fewer hard-hit fly balls and therefore induce more outs. There actually seems to be some data to suggest that there is some method to the madness for the wide range of pitchers acquired by Colorado this off season.

We hoped you liked reading Mile Fly City? by Jeff Zimmerman!

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Jeff writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won three FSWA Awards including on for his MASH series. In his first two seasons in Tout Wars, he's won the H2H league and mixed auction league. Follow him on Twitter @jeffwzimmerman.

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Logan Burdine

In Oakland, aren’t most flyballs weak? Nobody has ever been successful in Colorado with a ground ball % as low as Moscoso’s.


I disagree.


Doesn’t Oakland have enormous foul territory that turns a lot balls that would essentially go unrecorded as foul balls into IFFBs? Also, HR/FB rates aren’t going to do you much good unless they’re adjusted for parks, if not also competition.