Mark Simon from ESPN’s Stats and Info tweeted out about the Yankees rotation and a new stat that ESPN developed. Now, I’m not a stats wizard, but in the small print there, it says it’s based on earned runs and innings pitched, which makes it sound like some variant of the “quality start.” I don’t have an issue with that at all and I’m sure Simon et al did some work to improve things.
It does make me curious. Using win probability, is there a certain point of innings and earned runs that gives a team something north of a 75% chance to win? Because of how WP is calculated, it’s going to have to be a very, very big sample to get anything meaningful, but I think we have that (or can figure it out.)
Oh - why 75%? I know that teams don’t start out at 50%, but I think that if we use that as the theoretical starting point, getting the team “halfway to a win” is a pretty nice measure. I’d certainly be open to changing that if someone can come up with a better reason.
Am I right or wrong here? Is WPA a good tool for this? Is this even possible? Is this already out there?