Sunday, September 21, 2014
Negative Runs Created
?There's a thread here asking about negative wRC+ and wRC.
The point that is missing is the context of runs. You can have 9 guys that are all league average, and this team will score 4.5 runs, which is 0.5 runs created per player. You can replace one guy with a pitcher-as-batter, and keep the other 8 guys the same. This team will score 4.0 runs. Since the 8 guys were each worth 0.5 runs created when the 9th player was someone like them, we reason that they are STILL worth 0.5 runs when a pitcher-as-batter is in their midst.
And if the 8 guys are worth 0.5 runs created, that makes them worth 4 runs. Since the team of them plus the pitcher-as-batter scored 4 runs, we deduce the pitcher-as-batter created 0 runs... even though he did actually get on base, and score runs, and drove in runners.
And if you had Ben Sheets batting, this team would score 3.9 or 3.8 runs, and so, he'd deliver "negative" runs.
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And this is the hard part: if you had 9 Ben Sheets batting, they would certainly score more than 0 runs, and certainly not negative runs.
So, you really have to establish the ASSUMPTIONS for the stat. One set of assumptions leads to Sheets being negative runs. Another leaders to Sheets being positive.
And one set of assumptions will lower the RC of the OTHER batters depending on who is their teammate, while the other assumption tries to maintain independence.
Choose your poison, but don't tell the other person that he's wrong. You aren't arguing results, but rather reasonableness of assumption