Reached-on-error run value dropped ~11% and flipped below the single from the 1980s to today — real effect or noise?
I've been comparing linear weights (event run values built by averaging RE24 over every occurrence) for two MLB eras: 1985–1990 vs 2023–2025. Most of the movement I can rationalize, but one number I can't.
Reached-on-error (ROE):
- 1985–1990: +0.499 runs
- 2023–2025: +0.446 runs (about −11%)
The strange part is the flip relative to a single:
- 1985–1990: error (+0.499) > single (+0.461)
- 2023–2025: error (+0.446) < single (+0.472)
So in the '80s a reached-on-error was worth more than a single; today it's worth a bit less. For context, most other events either held steady or moved in directions I can explain: the single barely budged (+0.461 → +0.472), walks rose (+0.304 → +0.329), and the generic out got slightly more costly (−0.265 → −0.274). ROE is the one event that both dropped meaningfully and swapped ranks with the single.
My questions:
- Is a ~11% shift in the ROE weight actually meaningful, or is it within the noise you'd expect given how relatively rare ROE is?
- If it's real, what's driving it? Fewer extra-base advances on errors today (better fields, better positioning)? A change in the type of misplays getting scored as errors? Official-scorer discretion drifting over the decades? Something about the run environment itself?
- Has anyone tracked ROE run value across seasons/decades? A pointer to that would be great.
Both sets are RE24-based linear weights (the "average" across all 24 base-out states) for each era. Thanks in advance.