MLB Model Notes
The MLB model has evolved a lot over the years. After a stellar 2014, the high inherent variability of the sport sent us on a bit of a trip. I started chasing CLV too much in 2015, and let it negatively shape my model. Then I started denouncing CLV, and that didn't help either; I was in a little too deep to revert to the 2014 model at that time.
Beginning with the 2018 season, the model now resembles what it was in 2014; but with the addition of things like exit velocity data, which has been a revelation.
The NHL and MLB will duke it out for best profitability in the long-run; consistency driving the NHL, while volume drives MLB. NHL will be preferred by novice bankroll managers, while MLB will favor experienced bankroll managers.
We are in the throes of a million-to-one streak of negative variance that has been nothing short of incredible. I don't hold it against the model; that's just baseball being baseball, especially with the new super-juiced "variance balls" they are using this year.
I made the following minor adjustments, though, because it is hard to endure a run like this lying down:
Increased the importance of exit velocity for hitters and pitchers.
Increased the weighting factor of the current season exit velocity vs. prior season.
Increased the weighting factor of realized results vs. projections because exit velocity numbers are less noisy, and now they are more pronounced in my numbers (see adjustment #1).
Decreased recent form adjustments for pitchers and increased recent form adjustments for hitters.
I addressed a platooning issue that inadvertently made declining hitters better, and improving hitters worse due to platoon figures mistakenly anchored to long-term realized results, diluting the core metrics we use to measure hitters.