Friday, May 25, 2012

Three True Outcomes: Clearing the Mechanism?

Bonus points if you get the “For Love of the Game” reference.

            In my previous two posts, I went over two of the more commonly referenced sabermetric statistics (BABIP and HR/FB) when it comes to assessing how lucky (or unlucky) a player has been over a small sample.  This “luck” may just involve the interaction between the ball and the bat or the field, but can also be related to the positioning of the fielders (as with BABIP).  In attempting to judge the “true” value of a pitcher or hitter, however, sabermetricians have tried their hardest to isolate those aspects of the game that involve just the pitcher and the batter, and nothing else (“clearing the mechanism,” if you will).  This leaves us with what most stat guys call the Three True Outcomes: strikeouts, free passes (walks / hit-by-pitches), and home runs.  These outcomes have formed the canon of Defense Independent Pitching Statistics (DIPS).  How well do these few statistics actually measure the “true” ability of a player?

            Obviously, there can be a bit of discussion as to whether or not these three outcomes are really “pure.”  Yes, it is clear that any at-bat that results in the ball being put into play introduces variance from the skill and positioning of the players in the field, and therefore only the set of outcomes {BB, HBP, K, HR} should be considered.  The rest of the outcomes should probably be considered through the lens of BABIP.  While this seems just fine when it comes to judging the skill of pitchers, it really is insufficient to judge the worth of a hitter. 

Take a look at the true-outcome stats, as well as other relevant numbers, of three marquee outfielders in 2011 (note that ISO represents Isolated Power, which is just Slugging Percentage minus Batting Average):

Nick Swisher
Andrew McCutchen
Carlos Beltran

None of these players really separate from each other using the true outcome stats, but it becomes clear upon further inspection that Swisher is an inferior commodity, and it may be a matter of personal preference as to which of the remaining two you would want.  Why? 

            One thing that the True Outcomes ignore is speed.  While this has little to do with pure hitting ability, it certainly can make a player much more desirable and productive.  McCutchen stole 20 more bases than either of the other players.  While his batting average and on-base percentage were almost identical to Swisher’s, it can be assumed that his speed accounted for the slight advantage he held in isolated power, as he could leg out a couple more doubles and triples with that extra speed.

            As for Beltran, it is clear that, to some extent, his high BABIP contributed to a higher batting average than the other two (his career BABIP is right around .300).  However, it appears that he has an advantage over the other two players not in home-run power but in inside-the-park power, allowing him to gain a 20-point advantage in slugging without an advantage in the traditional power category, home runs.  Upon further inspection, Beltran hit the second-highest percentage of line drives in his career in 2011, producing a number of doubles and triples that he hadn’t produced in several years.  It becomes clear that you can still provide extra value by hitting the ball hard inside the park, even if you don’t hit more home runs than other players.

            While the true outcomes can form a pretty comprehensive representation of a pitcher’s performance (and I’ll get into this more later this week), it seems like a few other factors need to be considered with hitters.  A player’s speed contributes to his batting average (through BABIP), stolen base totals, and slugging percentage, and thus should not be taken lightly when considering performance.  Also, there is a good bit of variability of performance that can be found between players that have the same home run total, as players who can add a good amount of doubles and triples are much more valuable and likely to have consistent success over the course of a season or career.

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