With the great East Coast snowstorm of 2016 having rolled through this past weekend, I found myself with some unexpected free time. I took some of that time to complete a task that I should have done months ago. I finally updated the 2015 PAR numbers to be derived from stats including those accumulated during the 2015 season. As a quick reminder, PAR is built upon five years worth of league-wide data. During the season, that data comes from the five previously completed seasons. However, when a season ends, I adjust the numbers to use the recently completed season in place of the numbers from five years prior. So up until now, the ’15 PAR totals were based on data from 2010-2014. I have now replaced 2010 with 2015 stats. Normally, this post-season adjustment has minimal impact on the numbers and certainly wouldn’t be worth its own blog post. However, there were some interesting outcomes this time around, so I’m going to take this opportunity to chronicle them.
First, this update caused a slight uptick in cumulative offensive PAR and a similar downswing for pitchers. Across the league, these adjustments caused the league Batting PAR to increase to 201, up approximately 12 points, while pitchers dropped 11 points to 264. In a perfect world, both totals would be right around 225, which is the number of points above last place that can be gained in all of the batting and pitching categories. But as we’ve seen in almost all of the PAR numbers I’ve calculated to date, batters have fallen short of this total while pitchers have far exceeded it. This is because there has been a consistent decline in offensive numbers over the time period I have examined, with pitchers going the opposite direction. But we’re finally getting closer to the ideal league totals since the five year window is now almost exclusively seasons in which pitchers dominated. The reason for the adjusted increase in offense and decline in pitching is because 2015 replaced a 2010 season that was far better for pitchers, meaning the hurdle for earning points above replacement for hitters has gone down while pitchers have a higher obstacle to exceed.
On an individual player basis, most hitters saw their PAR increase slightly while pitchers dropped a bit. This was pretty consistent across the board, but a few noticeable changes are worth mentioning. First, the MVP race became extremely interesting in part because Josh Donaldson and Paul Goldschmidt had nearly identical PAR totals for the Jackalope. Prior to the update, both players had matching 8.45 PAR, with an ever so slight edge to Goldschmidt when expanding it to the third decimal place. But now, Donaldson has passed Goldschmidt as the Batting PAR champion, 9.35 to 9.29. The reason why Donaldson received more of a boost is because stolen bases became a little less valuable in the revised formula, which dinged Goldschmidt a bit. Of course, league members had already deemed Donaldson more valuable anyway, having named him the league’s MVP this season. There were a few place swaps down the Batting PAR leaderboard as well, but the top two switch was the most noteworthy.
On the pitching side, the changes were more consistent. All of the top pitchers saw their numbers go down by just about the same amount, so there were no changes to the Pitching PAR top 10. But there was an interesting change when looking at the historical numbers. Prior to this update, Jake Arrieta’s 16.32 PAR was the highest single season mark in recorded PAR history (2010 to present), just barely edging Justin Verlander’s 16.31 in 2011. However, Arrieta’s official PAR for 2015 has now dropped to 15.64, which drops him behind Verlander and 2014 Clayton Kershaw. It is difficult to compare players from different seasons, but PAR is one tool to do so. Arrieta had one of the best pitching seasons in league history, no matter how you look at it though. Kershaw and Zack Greinke remain solidly in the top 10 single season Pitching PAR (since ’10) with their ’15 seasons as well.
Now I will start working on calculating PAR numbers for more past seasons. 2009 will be up next, with a goal of completing every year since 2005 before the start of the upcoming season. Stay tuned for that.