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BWAA MVP: RBI and PA w/ Runners On; and some Astros RBI data too

With the recent discussions on the inaneness with which BWAA MVP's are often chosen, I figured it'd be worth it to drive home a point with some statistics.  Ryan Howard received a ludicrous twelve first place votes, mainly because he had a staggering 146 RBI.  But RBI isn't a good indicator of a hitters ability, it's just an indicator that he had guys who got on base in front of him and because he succeeded in putting the ball in play sometimes, drove them in.  Want to call B/S? Hold off for a few paragraphs.

For Howard, 2008 provided him 353 PA with ROB and total of 483 ROB in those PA, meaning -- if we exclude the RBI Howard collected by driving in himself via HR, a stat known as Others Batted In (OBI) -- Howard converted around 20% of his potential OBI in to OBI, or he had 20% OBI% (OBI% click for definition).  That's actually a hefty amount, and good for first in the NL among batters with a minimum of 500 PA.

But was it the fact that Howard lead NL regulars in OBI% that helped him accumulate RBI, or was it that was almost as high on the list for PA with ROB or just tROB in general?  To figure it out, I ran correlations for PA with ROB, tROB, and OBI% on OBI for MLB in 2008.  The data set came from Baseball Prospectus Sortable statistics (as has just about all of that stats I've thrown out so far).

These were the results:


While OBI% does seem to exert some influence on OBI, and therefore RBI, clearly having more PA with ROB and, actually slightly more so, having more ROB drives OBI and RBI production -- almost entirely so.  To rephrase that: RBI has almost everything to do with opportunity -- rather than skill.  

Ipso facto: RBI should never be used as justification for someone being an MVP.  Saying that is essentially saying that the guys in front of Howard (usually Rollins and Utley) were the most valuable.

Playing around with some the Astros data from 2008, our top 10 OBI producers, sorted by OBI% looked like this:


Pretty disparate results.  Miguel Tejada was dismal at converting RBI opportunities, while Mark Lorretta was clearly an incredibly valuable PH.

As a team, here's what our correlation coefficients looked like:


Spot on, just about, with the MLB-wide data.  No skill: just opportunity.