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Digging Deeper: Sorting Out Astros' Line Drives and Fly Balls

NEW YORK - SEPTEMBER 26: A batted ball hit by Bill Hall eludes a dive by Yankees' right fielder Nick Swisher. We don't know if it's a line drive or a fly ball. (Photo by Mike Stobe/Getty Images)
NEW YORK - SEPTEMBER 26: A batted ball hit by Bill Hall eludes a dive by Yankees' right fielder Nick Swisher. We don't know if it's a line drive or a fly ball. (Photo by Mike Stobe/Getty Images)
Getty Images

OK, it's time to forget all the fun discussions of the hot stove and Hall of Fames votes. I'm back with more analysis of batted ball data.  Please bear with me. This may not seem like fun to some of you.  But I'm intrigued by drilling deeper than our normal characterization of a player's BABIP.  I think we can obtain greater insight by focusing on batted ball types and the directions of the balls.

Last week I examined Carlos Lee's batting average on line drives and concluded that he was relatively unlucky in getting hits off his hard hit balls.  My conclusion: we should expect Lee to have more line drives turn into hits next year.  I told you that I would be back with more on Astros' batted ball batting averages this week.  So, here I am. 

It's always a good idea to start off by linking an article for you to read, if you're interested in this subject.  And I re-read this article by Mike Fast at the Hardball Times ("Confessions of a DIPS Apostate") before I started my evaluation.  The article is worth reading, first, because the mocking title is funny, and second, because the article is a thought provoking use of Gameday's pitch f/x to examine fly balls and line  drives.

This time I will separate the fly ball and line drive data by the three outfields areas (LF, CF, RF), using Bill James On-Line data.  Since the Astros over the years have acquired hitters who they think will hit well in the unique outfield dimensions of Minute Maid Park, this may give a hint of why they do that or whether it is likely to yield returns.  Also, Fast's article suggests that the field that balls are hit to is an important influence over whether a line drive or fly ball becomes a hit.  As I examined the data by field, I realized how small the sample sizes are for some of the young players who had a half season or less in the majors. For example, I excluded Brett Wallace's line drive data by field because he hit so few line drives to each field.

Line Drives

In my previous article on Lee's line drives, I concluded that the batting averages on line drives tend to regress toward the league average lind drive batting average, i.e., a hitter's batting average line drive varies from the league average in a more or less random fashion.  The major league average batting average on line drives in 2010 was .724.  (Generally, the league averages have been in the .720 - .730 range.)  Carlos Lee had  baseball's lowest batting average on line drives (.612) which probably reflects some bad luck.

So, what other Astros had line drive batting averages which may suggest the liklihood of significant regression?  Besides Lee, Barmes (.676), Wallace (.688), and Castro (.647) were signficantly below the 2010 major league average, and could well see an improvement in line drives which turn into hits.  Keppinger (.787) and Chris Johnson (.804) are the Astros' hitters who are more than 50 points above the league average batting average on line drives. To the extent that line drive batting averages are relatively random, we shouldn't be surprised if we see regression by Kepp and CJ.

I don't think that we can make generalizations about the liklihood of regression for line drive batting averages by direction.  As Fast's article suggests, hitters generally hit the ball harder on pulled balls;  and as a result mean batting averages generally will be higher on the pull field and lower on the opposite field.  Since players vary in their tendency to pull the ball and hit to the opposite field, I would be careful in using the data to indicate luck in hitting. Also, the fact that different home ballparks may have different characteristics by field makes such generalizations problematic.

Fast's article derives the following major league contact batting averages on line drives: .753 (pull field), .736 (CF), .697 (opposite field).

Assuming a starting lineup of Lee, Bourn, Pence, Johnson, Barmes, Hall, Wallace, and Castro, I derived a simple average for 2010 line drives by the current "team:"  LD-Left: .727, LD-CF: .750, LD-RF: .647.


To provide a comparision to Fast's pull data, I separated pull field LD batting averages for the current Astros' team by RHB and LHB, shown below.  Keep in mind that LHBs consist only of Bourn and Castro, since I excluded Wallace due to sample size.


RHBs  .732

LHBs  .614

MLB   .753

The current Astros starters' 2010 LD batting average appears to be lower than the major league average for pulled balls.  The two LHBs are far off the norm, but it appears that neither Castro or Bourn is primarily a pull hitter.  Bourn's highest batting average on line drives is to CF, both in 2010 and for his career (.883, .810), and he normally hits the fewest line drives to the pull field.  It may be too early to reach any definitive conclusions about Castro, but his highest LD batting average was to the opposite field (.853). 

Chris Johnson has an interesting pattern, since his LD batting average is normal for the pull field (.750), but rises significantly for liners to CF and RF (.825, .857).  Keppinger also is much higher than average for CF and RF liners (.765, .828).  In the past I have speculated that Chris Johnson's "all field" approach to line drives may allow him to sustain a higher than expected BABIP.  I looked at LD batting averages by direction for the MLB hitters with the highest batting average on line drives for the period 2007-2010, but I couldn't detect a pattern, either in terms of the distribution of liners among the three fields or distribution of LD batting averages between the three fields.  The only player who repeats a Chris Johnson-like pattern over the three year period is Delmon Young.  It's also worth noting that the sample size for Johnson is so small that I'm not sure we can definitely say that he is an "all field" line drive hitter.

It does seem that the Astros may tend toward higher batting averages on balls hit to CF, which would make sense, given the huge CF in MMP.  Bill Hall had line drive batting averages well above normal for his pull field (LF) and center field, and below normal for the opposite field (.789, .813, .556).  This  may be influenced by the peculiarities of Fenway Park. Although the sample size is small, Manzella also has an unusual pattern on his batting average for LDs.  Manzella's average to the opposite field was extremely low (.375), but his average to the pull field was 1.0.  Yes, 10 for 10 on line drives to LF.  This may mean nothing because 10 line drives is a small sample--but all 10 falling for hits is worth noting.

Fly Balls

Fly balls are interesting because overall fly balls typically have a low batting average (.219 for all ML batters in 2010), but the batting average usually varies signficantly by direction.  The Fast article indicates almost a 300 point contact batting average differential between the pull field and opposite field for fly balls.  Home runs are a big reason for the differential.  For example, the article shows a differential of approximately 230 points for the pull field between BABIP (which excludes HRs) and contact batting average (which includes HRs). 

Because fly balls are related to a hitter's power, fly ball batting averages shouldn't be expected to be randomly distributed.  While luck surely enters into whether some fly balls are caught, Fast's article concludes that fly ball batting averages to the pull field appear to be a repeatable skill.  You can see this by looking at the above average career batting averages on fly balls for classic HR hitters.  For example, Berkman, Alex Rodriguez, and Adam Dunn have batting averages on fly balls well above .300 (in contrast to the typical .219) for the period 2002-2010.   From the previously mentioned article, I use the following batting averages on fly balls as the norm: Pulled field .452, CF .217, Off-field.162.

Again, I look at a prospective Astros lineup's 2010 batting average on fly balls.(I included Wallace for this comparison, because his fly ball sample is a little bigger than the line drive sample.)  The Astros' batting average on fly balls is slightly higher than the MLB average, .230 vs. .219.  The Astros' fly batting averages by field are: .326 LF, .226 CF, .256 RF.

The fly ball batting averages for the pull field broken down by LHB and RHB:

RHB  .450

LHB   .717

MLB  .452

The Astros' fly ball batting average on pulled balls is about average for the RH part of the lineup.  But the LH part of the lineup has a far higher batting average to the pull field.  However, a caution is necessary: given that only three hitters are lefties, and two (Wallace and Castro) played only a partial year, the LH result probably is too small a sample size to make anything other speculative conclusions.  That LHB differential may not be meaningful.

That said, maybe we can be a wee bit encouraged for Wallace and Castro. (Given their offense in 2010, any encouraging sign is good.)  Wallace's batting average on fly balls to CF and RF was good (.412 and .444); and his batting average on fly balls to the off field was bad (.133) which isn't unusual.  When Castro pulled a fly ball, he had a good batting average (.545), but his battting averages to LF (.036) and CF (.118) were terrible.  Castro and Wallace have been hitting most of their flyballs to the opposite field and centerfield.  If both players can pull more fly balls, there slugging and batting average will improve.  Given their sample sizes, it's possible that the off-field distribution of fly balls isn't reflective of the future distribution of fly balls for these two young hitters.

The most noticeable part of Carlos Lee's fly ball batting average is that his fly balls to CF fell safely at an attrocious rate (.074).  Although Lee's pull fly ball average (.365) is below MLB average, it is consistent with his career average (.362) and 2009 average (.368).  However, his fly ball batting average to CF is less than half of his CF-fly averages for both 2009 and his career.  Does this mean that Lee's diminished lack of power is showing up in weaker fly balls to CF?  Maybe.  Could it be a fluke?  That's possible too.

Chris Johnson had a batting average substantially better than normal when he pulled the ball to LF (.529), and he had above average batting averages when he hit flies to CF and the opposite field (.270 and .273).  Maybe this is a small sample size artifice, but it's also possible that this is an indication of good power to all fields.

In case you were wondering why the Astros feel like Hall is a good match for Minute Maid Park, he had a scorching .619 batting average on fly balls to LF. 14 of Hall's 31 fly balls to LF were HRs.  For his career, Hall's batting average on fly balls to LF is .503.  So, he has real power as a pull hitter. Over his career, 36% of his fly balls to LF turned into HRs.  Hall had an above average .257 batting average on flies to CF in 2010, with 3 doubles, 1 triple, and 2 HRs.   Hall doesn't have a good batting average on fly balls to the opposite field, which isn't unusual for most hitters.

Barmes is the other hitter who was acquired with the idea of taking advantage of the Crawford Boxes.  However, Barmes batting average on fly balls was an unimpressive .156 in 2010, and his .304 batting average to LF is below average for a pull hitter.  Barmes' career batting average to LF is somewhat better, .341, though it is less than I  expected.  Since almost all of Barmes' HRs are hit to LF (he has hit only 3 HRs to CF or RF in his career), hopefully his 2010 performance is aberrant.  One might also hope that the short LF distance at Minute Maid will juice up his HRs over 2010.  At this point, though, the most positive part of this analysis is the liklihood that his line drive batting average will regress toward the mean and increase his batting average over 2010.

So, I'll bring this discussion to an end.  I hope we learned something about the Astros' hitters.  As you watch Astros' games, maybe can make a mental note of the type of balls hit by each player and whether the direction of the ball is likely to produce a hit.