Measuring Sticks, Old and New

Well documented is the transcendence of baseball from statistically cognizant to analytically driven. This transformation occurred over the course of decades; it has come about haltingly, nonlinearly, and the result is the hyper-computational landscape of baseball today. 

Below is a quick juxtaposition of a couple common performance measures of distinct eras. First the relationship between two distinct measures will be briefly established. Second, players who most benefit, or suffer, from current standards will be listed.

For a measure of traditional performance, double, triples, and home runs have been rolled up into a total count for extra base hits. Extra base hits represents just about the most traditional single statistic one could draw upon. It is a counting stat, which incorporates metrics that have been tracked for over a century. For a modern performance measure, wRC+ is utilized. wRC+ incorporates, and controls for, far more information which makes it a standalone offensive rate stat commonly employed today. 

Count stats, like home runs and doubles, are still obviously part of what more modern statistics draw from. As a result, one still anticipates a meaningful relationship between both old age and new age metrics. 

To illustrate these metrics of choice, below is a figure which visualizes either stat for each qualifying batters in 2019.

Simple count stats, it seems, still relate fairly consistently to a modern metric of choice. But they do not relate exceptionally closely. The correlation between these two metrics in 2019 for qualifying batters is 0.724, making them clearly linked, but not intimately so.

So which players most exemplify the disconnect between traditional and modern statistics in 2019? To evaluate and rank them, “expected” wRC+ was calculated based on simple linear regression (represented by the turquoise line in the figure above) using each players number of extra base hits as the singular explanatory variable for that regression. 

First listed are those players who underperformed their “expected” wRC+ according to the number of XBH’s they recorded. These are the players whose reputations might suffer in today’s iteration of baseball; these are players whose seasons might have been over exaggerated in years past. These seasons might have warranted larger payouts in free agency than we have come to expect today.

Ah, Rougned. Rougned Odor, with three 30 home run seasons and one trigger-happy fist all by age 25, might have been considered a franchise player in another era. Today though, baseball reference credits him with just a career 89 OPS+ and his long term contract is unfortunately considered to be a general bust. Meanwhile double play partner Elvis Andrus, whose offensive renaissance seems to have sputtered following a broken bone (by way of HBP) suffered in 2018, would likely be looked at differently too in another era as a shortstop capable of 40+ XBH’s and 70+ RBIs. As it stands, the Rangers have a middle infield which they are on the hook paying and can only hope for adjustments going forward.

Current free agent Nicholas Castellanos is another interesting case. Yes, he had a strong season at the plate, particularly down the line with the Cubs, and 58 doubles really does stand out, but his efforts would almost certainly have been of greater appeal a decade ago. Eric Hosmer, meanwhile, isn’t doing a great job masking his mediocre output with decent counting stats now entering the third year of his huge deal with the Padres.

Next, those players who outperformed their XBH totals.

It is always nice to see modern stats indicate how much Mike Trout (or Christian Yelich, or Alex Bregman) bring to the table outside of stacking up the hits they collect. This list is made up of proficient big league hitters, not a single one is below average by wRC+’s measure. Their abilities to get on base, limit double plays, and generally add value in a plethora of ways is better captured now than ever before. In today’s game, they get even more appropriate credit than they might have before now.

This list does include some players whose differential is boosted by factors like BABIP, as is the case of White Sox teammates Tim Anderson and Yoan Moncada. Still, this list as a whole would have been taken for granted significantly with only count stats at any viewers disposable.

Worthy of final mention too are those players whose 2019 aligned perfectly across these measures, or whose “predicted wRC+”, based on XBHs, matched exactly their totals in reality . Those players: Asdrubal Cabrera (98 wRC+), Paul Goldschmidt (116), Trea Turner (117), and Josh Bell (135).