I am not a statistician by any stretch of the imagination. Nor am I a sabermetrician. I can barely follow along with the conversation threads with the big brains on Tango’s website. As a result, I have to take some things on faith. Sometimes I feel good about that, sometimes not. The things I am taking on faith for this first Run Values view are giving me heartburn. Here’s what’s happening:
In the previous view, we established a run environment for each league year. That is, we determined how many runs were scored for every plate appearance and for every out. In this next view, we are adding a run value to the runs per out for every non-out batting outcome. For example, let’s say that in 2009 the RperOut for my league was .172. That’s basically saying that, no matter the outcome, stepping up to the plate in 2009 was worth at least .172 runs on average. That RperOut establishes a baseline to which successful outcomes will add value. How much value? Here’s where the heartburn comes in.
The value added is a constant for each event. Across all years and leagues. A walk is worth 0.14 runs more than an out in every year, league, planet, park, etc. It’s difficult to accept for real world historical MLB and it’s even harder to accept in OOTP where the baseball environment can be much different. I have been looking, and will continue to look, for an explanation of how these constants were derived. Haven’t found one yet and I’m anxious to move forward, so I will accept them for now. However, when I start getting wacky results for my OOTP stats, this is the first place I am going to look.
It’s to do with Run Expectancy, and this Tango post and this article talk about it, but I was having some trouble parsing it, so I am leaving it for now, but with some misgivings. So to recap, this view we are adding an expected run value to the runs per out for every non-out batting outcome. Here’s that view:
CREATE OR REPLACE VIEW vRunValues AS
SELECT l.year
, l.league_id
, l.rperout
, l.rperout+0.14 AS runBB
, l.rperout+0.14+0.025 AS runHB
, l.rperout+0.14+0.155 AS run1b
, l.rperout+0.14+0.155+0.3 AS run2b
, l.rperout+0.14+0.155+0.3+0.27 AS run3b
, 1.4 AS runHR
, 0.2 AS runSB
, (2*l.RperOut)+0.075 AS runCS
FROM vLeagueRunsPerOut AS l;