Projection Accuracy: Late March Hitter Rate Stats
I’ve been slowly working my way through the hitter projections and that journey comes to an end today as I examine how each projected hitter rate stats stand up. Besides batting average, I turn each of the counting stats into a rate by dividing by plate appearances. Finally, I adjust each value to the actual league rates. Again, any combination of projections stick out along with the BAT.
For reference, here are the projections used.
- Steamer (FanGraphs)
- ZIPS
- DepthCharts (FanGraphs)
- The Bat
- The Bat X
- Davenport
- ATC (FanGraphs)
- Pod (Mike Podhorzer)
- Masterball (Todd Zola)
- PECOTA (Baseball Prospectus)
- RotoWire
- Razzball (Steamer)
- ZEILE (Fantasy Pros)*
- Paywall #1
- Average of the above projections
To create a list of players to compare for accuracy, I took the NFBC Main Event ADP (players in demand at that time) and selected the hitters in the top-450 drafted players (30-man roster, 15 teams in the Main Event). To determine accuracy, I calculated the Root Mean Square Error (RMSE) for two different sets of values. RMSE is a “measure of how far from the regression line data points are” and the smaller a value the better. Additionally, I included the actual and league average rates for reference. Read the rest of this entry »