Setting Guidelines For an Overperformance Metric

About a week ago, I finished creating some simple stats for the chance a hitter underperforms. Now it’s time to find the overperformers. These are the potential breakout guys every owner hopes to hit on and help carry their team to a championship.

To start with, a breakout needs to have some set baseline values. I went to Twitter to help find a baseline value to use. I’ll start with a playing time boost.

A hitter is projected as a bench bat to start the season. How many additional PA over projection (200 PA) would you consider him to break out?

Assume as .310 wOBA hitter (ex. Alex Gordon, Kevin Pillar, Andrelton Simmons).

— Jeff Zimmerman (@jeffwzimmerman) November 13, 2017

By weighting each of the groups, the expected change works out to a 227 PA jump (113% increase). The value I found for underperformance was 222 PA. I expect the difference to be more as people are more inclined to preventing losses than chasing gains.  With the values are so close, I and considering putting both values at 225 PA.

For 2017, here are the players who met this criterion.

The list is full of rookies and failed prospects. They were projected for a .298 wOBA but posted one at .341 for a difference of 43 points which will end up being close to the wOBA jump needed for a breakout.

Now for the production increase. Like in the previous article, I asked for a jump in on-base percentage but I am going to use wOBA which is on the same scale.

For a .310 OBP hitter to breakout, what would his OBP need to be?

— Jeff Zimmerman (@jeffwzimmerman) November 14, 2017

The jump worked out to a 40-point jump (13% increase) needed to make the overperformance threshold. In the previous article, a 35-point drop was considered underperformance. Again, it took more movement to overperform than underperform.

And here are the hitters who beat their projections by the 40 points.

I can’t seem to find a unifying theme to the list. It contains superstars and bench players. It points to just about anyone at the top and on down the talent spectrum breaking out.

Finally, here are the players who are on both lists.

When I think of true 2017 breakouts, this list contains those hitters. I feel I’m off to a good start but who knows.

Finally, how do the RotoGraphs readers think of these breakouts? Too many names? Too few? Am I missing anyone? Once I have the benchmarks, I will move onto creating an overperformance metric to go with my underperformance one.