How Much Will Cruz Regress to the Mean? (3rd of 3)

cruz3In the first parts we identified Nelson Cruz’ Flowchart Profile (Power: yes; Line Drives: no; Plate Skills: no), and learned that among hitters with that skill-set his career stats (.829 OPS) are considerably above the mean (.754 OPS).

More than that, he’s coming off two seasons (.833 and .859) that are above his career norms.

So, first off, we’re not looking at “untapped potential” or anything like that.  The only question is how much downside could we see.  And when.

OK that’s two questions.

First question first.

We know that Cruz out-performs his “statistical fundamentals.”  Is he lucky or good or both?


The first thing that accounts for his “above the mean” performance is his plus-plus power.

Nothing drives up OPS like power, since home runs are both (1) a non-out that counts for on-base percentage, and (2) a hit that contributes to slugging percentage four times as much as a single and twice as much as a double.

And, as we noted in the first part, Cruz ranked 28th out of 537 (among MLB hitters for which batted-ball stats are available [2002-14]) in producing “authoritative launch.”  That’s in the top 5% of hitters.

Even among those we classify as having “above-average power” (measured as “authoritative launch”), Cruz has a much-higher-than-average home run rate (average for all hitters: 7.2% of launched balls clear the fence; for all those with above-average power, 9.5%; Cruz since 2009, 14.1%). [Only Thome and Bonds top 19% since 2002.]

Plus he’s been very consistent since 2009 with that power.

So it’s not surprising to see him out-perform his skill-set-peers in that respect.


The second thing that accounts for his “above the mean” performance is good fortune on BABIP.

Cruz has a career BABIP of .299.

And “everybody” knows that BABIP of .300 is average and anything else is just random noise.  Just like 15 minutes and car insurance I suppose.

Except not.

We came up with our “hits-in-play index” (HIPI) that measures likelihood of getting on base with batted balls.

Here’s your handy-dandy cheat sheet:

120+ 0.328
100-120 0.305
80-100 0.293
less than 80 0.279

Cruz has a HIPI+ of 79.

Based on his batted-ball profile, Cruz has been producing batting averages higher than he “should” get.

It is very, very reasonable to expect Cruz to regress toward the mean on batting average, and, thus, OBP.


So what kind of downside are we looking at?

Well, we have two things here.

  1. Decline in outcomes due to “regression to the mean” (for players outperforming skill-set).
  2. Decline in outcomes due to decline in skill-set.

On the on-base metric, we would expect Cruz to regress to the mean.  His low line-drive rate indicates his batting average is likely to decline.  If it happens, it would cost him maybe a couple dozen points of OPS.  Which still puts him around .800 — so we’re not talking cratering here.

On the power metric, I do not see decline for Cruz simply due to “regressing to the mean.”  He has established ability to “launch.”  His 2014 numbers on that score were not out of line with what he’s been doing since 2009.

Therefore, so long as Cruz maintains his skill-set, he ought to continue to produce offense at around .800 OPS.  And that makes him one of the best players on the Mariners and one of the best DHs in the game.

But how long will he maintain his skill-set?  Well that will have to be another article.



2 thoughts on “How Much Will Cruz Regress to the Mean? (3rd of 3)

  1. Nice breakdown, Spec 🙂 It’s interesting to see how his entire game is based on pure power; that’s not a player type we’ve had in Seattle since Branyan…at least, it’s not a player type that’s been represented by a GOOD player since Branyan, and Sexson before him.

    I knew there was a reason I wanted the M’s to ditch Olerud and sign Thome a decade+ ago!

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