Introduction

Tomorrow (January 25) we will learn the results of the 2022 Hall of Fame (HOF) election by the baseball writers. Based on the public ballots, it appears that the one person with the best chance of being selected for the HOF is David Ortiz who is in his first year on the ballot. Since I have been discussing the construction and use of career trajectory graphs (made using the Shiny interface) in recent posts, I thought these graphs would be helpful in comparing the batting performance of Ortiz with a few of his contemporaries.

The FanGraphsBatting App

Currently, this Shiny app is live at https://bayesball.shinyapps.io/FanGraphsBatting/. So one replicate any of the career trajectory graphs described in this post.

For the interested reader who wants see the actual Shiny code, the R code is found here in my CareerTrajectoryGraphs package. The app.R script is self-contained — if you download this single file, it can be run within RStudio.

Using this app, I chose players whose midyear was contained in the five-year period 2004 through 2008 and who had over 10,000 plate appearances. The seven players selected with these criteria were David Ortiz, Alex Rodriguez, Carlos Beltran, Bobby Abreu, Adrian Beltre, Jimmy Rollins and Derek Jeter. This is an interesting group. Jeter was recently inducted in the HOF and Ortiz, Rodriguez, Abreu and Rollins currently are on the 2022 HOF ballot. Beltran and Beltre will be on the future 2023 and 2024 HOF ballots, respectively.

WAR Trajectory

Let’s compare smoothed WAR trajectories of the seven players graphed against age. It is clear that Rodriguez had the dominant WAR trajectory, especially during the ages 20 to 30. The other six players have similar trajectories. Looking at Ortiz’s trajectory (the blue curve), it seems that he peaked in WAR around age 30 and had relatively sharp increases and declines about that peak. In contrast, Bobby Abreu peaked around age 27 and showed a continuous decline in the following 10 seasons.

wOBA Trajectory

One gets a different comparison by considering the weighted on-base percentage wOBA. WAR is a measurement of a player’s total wins contribution — in contrast, wOBA measures the average contribution of a batter on each plate appearance. The smoothed trajectories of these seven players are more separated using the wOBA measure. Some interesting takeaways:

• Although Rodriguez is clearly the leader for most ages with respect to smoothed wOBA, Ortiz had a similar wOBA from ages 28 through 32.
• Ortiz declined in wOBA from ages 30 to 33 but his wOBA actually increased after 33 until the end of his career.
• Abreu had his best wOBA seasons from ages 25 through 28.
• Beltran and Jeter had similar wOBA trajectories.
• Beltre had a remarkable rise in his wOBA about age 30 and maintained high wOBA values in his middle 30’s until declining at the end of his career.
• Rollins was significantly less productive than the other six players with respect to wOBA.

wRC+ Trajectory

wRC+ is an improved version of Bill James’ runs created formula comparing to the league average and adjusting for ballpark effects. Comparing these smoothed wRC+ trajectories with the smoothed wOBA trajectories, they appear very similar. So the comments about the players’ wOBA trajectories would carry over to the comments about their wRC+ trajectories.

OBP Trajectory

Let’s try a traditional measure of performance, the on-base percentage OBP. Comparing smoothed OBP trajectories, we see that Abreu had the best OBP for the ages 24 through 33 and Rodriguez had a lower OBP with a similar trajectory shape. Ortiz and Jeter provides an interesting comparison — Jeter had a high OBP in his mid-20’s, while Ortiz excelled around age 30. Ortiz had a good OBP towards the end of his career while Jeter had a steady decline until age 40. Beltran had a clearly lower OBP trajectory than both Ortiz and Jeter, and Rollins and Beltre are at the bottom. We’ve already commented on Beltre’s unusual rise in batting performance in his 30’s.

HR Trajectory

Since baseball loves home run totals, let’s look at players’ HR trajectories. Here is where Rodriguez and Ortiz excel, although Ortiz excelled in the second half of his career. Next we see Beltran showing a standard trajectory shape, peaking about age 27. Beltre had a pretty constant trajectory pattern which contrasts with Abreu who declined in his 30’s. Both Rollins and Jeter had similar trajectory patterns at the lowest level.

K Rate Trajectory

Since home runs are generally associated with strikeouts, here are trajectories of smoothed K rates. I see three groupings — A-Rod, Abreu, and Ortiz had the highest rates, followed by Beltran, Jeter and Beltre, and then Rollins. Some of the players (A-Rod, Rollins, and Beltre) had significant rises in their K rates towards the ends of their careers. Rollins had a remarkably low K rate in the middle of his career.

Def Trajectory

Since we have Defensive Runs Saved (Def) available in the FanGraphs leaderboard, let’s look at smoothed Def trajectories. Some observations:

• Beltre and Rollins stand out with respect to fielding — Beltre in his 20’s and Rollins in his 30’s.
• After Beltre and Rollins, Beltran and A-Rod are the best fielders, although both players exhibited significant declines towards the end of their careers.
• Jeter’s Def values are clearly average, as his smooth hugs the Def = 0 horizontal line.
• Abreu was a good fielder in his early 20’s, but his fielding dramatically declined from 25 to 35.
• Ortiz had limited fielding as he was a designated hitter (DH) for most of his PAs. So as one might expect, his Def rating was in the -10 to -15 range for his entire career.

Who Should be in the Hall of Fame?

This is an interesting group of players to compare since it includes one person already in the HOF (Jeter), four people on the current HOF ballot, and two who will be on future HOF ballots. Here are some takeaways about these player careers from looking at these career trajectory graphs.

• Alex Rodriguez. Clearly A-Rod is the dominant hitter in this group judging by the WAR and wRC+ trajectories. Also he was a great fielder, at least for the first part of his career. On the basis of his hitting and fielding accomplishments, A-Rod should be a slam-dunk for the HOF. But for other reasons, he likely won’t be elected in 2022.
• David Ortiz had an interesting career. He was very mediocre in his 20’s and rose quickly to greatness around age 30 and he maintained a strong hitting record in his 30’s. His hitting was comparable to Rodriguez in his 30’s. Ortiz is very popular and is well-known for his hitting accomplishments in the post-season. He is believed to be a clutch hitter who excelled in important situations. He didn’t have great fielding stats since he was primarily used as a DH. It is notable that his WAR trajectory is similar to the other contemporary players in this group.
• Derek Jeter. Although Jeter is in the HOF, it is interesting that he his hitting performance is somewhat average in this group of seven (look at the wOBA graph). Part of the rationale for Jeter’s HOF election was on some notable fielding plays (we talk about Jeter’s famous flip play in Chapter 1 of our Analyzing Baseball with R book), but using modern fielding measures, Jeter is generally not thought to be a strong fielder.
• Bobby Abreu and Jimmy Rollins (both former Phillies) will likely not be elected to the HOF in 2022. Abreu was one of the best hitters in this group, but his fielding was weak towards the end of his career. Rollins, in contrast, was one of the best fielders but the worst hitter in this group.