Thursday, December 09, 2010
Bases, Outs by Event
This is how many bases are gained on each event. This is as pure as it gets. No adjustments, no fancy-schmancy divisions or multiplications. A straight addition of all bases gained per event.
For a HR for example, you add up all the bases the runners took from 1B and 2B and 3B, and you get 1.4 bases gained, and the hitter himself gains 4.0 bases, for a total of 5.4 bases. For the inning-ending plays (outs), I subtract the bases, hence -0.5 bases for strikeouts.
If you add up all the bases, divide by 4, you get exactly the total number of runs scored. (That should make David Smyth happy.)
Most of the event categories are obvious. The less obvious ones are FCSA is “fielder’s choice, safe”. ROE is “reached on error”. SAFE is “safe somehow”. XI is interference. NIBB is unintentional walks. The line separates the good from the bad events. The top part are batter events, and bottom part are runner events. DI is “defensive indifference”. OA is “other advance”.
ROUGHLY speaking, if you take bases and divide by 4, you get close to Linear Weights. For outs, subtract an extra -.18 runs per out for the current time period, and -.16 runs for the previous time periods.


Kind of weird having the event listed on the right. Seems like it should be on the left since we read left to right and each row of data is predicated on knowing the event basis.
To me, the data ordering should translate to a sentence. So, the first row of data would correspond to saying, “A home run from 1993-2010 was worth 5.41 bases, the same was true from 1969-1992, and it was just a touch higher at 5.43 from 1950-1968.”
That doesn’t happen easily when the event is on the right. On top of that, for the sake of chronology, it seems like all of the columns are reverse where they should be, but that’s a separate question of whether forward or reverse chronology is desirable.