The right now sucks. Let’s talk about the future. Specifically, a very important decision that’s loooming for the Diamondbacks in 2019/2020.
Should the Arizona Diamondbacks extend Paul Goldschmidt?
Now, this is a very difficult question to answer as there are many factors at play, but primarily (expected) performance and cost. This article will not focus on cost but will instead provide one means of analysis for Goldschmidt: player comps.
This is not meant to give a decisive, final answer on how Goldy will perform after he signs his extension (with whichever team). But it will give a look into similar players for the past and compare how they’ve performed as they’ve aged.
To start making a list of comps, the qualifying factors needs to be considered. Since Goldy is primarily being analyzed as a hitter, this analysis will focus on the primary input stats to offense: BB%, ISO, and BABIP. It also look at batters from their age 28-30 seasons, as this is comparing them to the same age as Goldy as the last three seasons. The overall criteria are:
BB%: ≥ 13%
BABIP: ≥ 0.330
This should get a really good grasp of players that were very similar to Goldy. Goldy’s combination of plate discipline/patience, power, and ability to hit for average are nearly impossible to combine. Which should make it no surprise that only six qualified hitters (including Goldy) since 1990 have managed to combine all of those factors over their age 28 - 30 seasons:
Goldy Comps Ages 28-30
Wow. 5 really really good hitters and Brad Hawpe. No offense to Brad Hawpe - he was a good hitters but no on the caliber of the other five hitters on this list. The Coors effect certainly played a role here (as it does for Helton). Helton will remain on this list but Hawpe will be removed as he had less than 700 PA for the remainder of his career after age 30.
The other four hitters - Jason Giambi, Todd Helton, Manny Ramirez, and Jim Thome - make for a solid but small group of comps for Goldy. One thing that makes this particular useful is that they are all roughly the same size as Goldy. All of these hitters are on the taller and stronger side of things. Manny Ramirez was the “smallest” of this group but he still comes in at 6’0” and 225 lbs per FanGraphs.
To do this comp, all four of these players will be analyzed from their age 32 (the first year of Goldy’s free agency) through age 38 (the seventh year of Goldy’s free agency). We don’t know how long Goldy will sign but seven years seems like a good range to go out to. Luckily for this analysis, all four of these hitters played through at least age 38 (a good sign for Goldy?) .
This analysis will look at each hitter’s BB%, K%, ISO, and BABIP year-by-year and an average will be taken for the group here. The main things to look at:
- How does the average trend over the 7 years?
- How much do the individual season’s vary within each stat?
The overall magnitude of any one stat doesn’t matter; we care more about how these stats tend to trend with age and how their compare, relatively, within each player.
The first thing to look at is BB%. There is not a ton of variation here aside from Manny Ramirez’s age 34 season spike. Beyond that, the overall trend tends to stay pretty even across the years, maybe managing a very slight decay. This is promising for a Goldy extension.
Next up is K% and the variation from year-to-year is even smaller than BB%. It does appears that K% increases gradually as a hitter ages - as one might expect, given that bat speed is likely to slow down as your age - but the overall increase may not be as much as one might commonly believe. Maybe this is because of the selected sample of elite hitters, but having the average K% increase from about 18% to 21% over the course of 7 years isn’t really a large jump.
Plate discipline skills (BB% and K%) seem to be doing well with age. Another positive for Goldy.
Ah, power. This graph is quite a bit more telling than the previous two charts as we’re seeing the first real sign of aging come, almost unexpectedly, from the power department. Now, keep in mind, that these guys ended up roughly around league average by the very end of their careers, so they still managed to have some power.
However, the roughly 100 point drop in ISO over the course of 7 years is something to factor into Goldy’s aging comp. Power is the biggest factor that makes these hitters elite. Fortunately for Goldy, his profile depends the least on power in this sample, but it should definitely be expected that his power numbers will drop as he ages - and so will his overall offensive output.
The last of the four skills is BABIP and it seems to once again hold pretty true. What’s interesting is that there is a fairly large drop (~.030) from ages 28-31 (averaged into one stat) and age 32 but from ages 32 on, it remains fairly steady.
What’s further interesting is that these players all had BABIPs, individually, over .330 in their age 28-31 seasons but they averaged, as a whole, .300 from then on. Jason Giambi seems to really bring the group down. Manny Ramirez and Todd Helton, the two highest BABIP’s from the group, did manage to maintain fairly good BABIPs throughout their careers as they aged.
BABIP is probably Goldy’s strongest skill of these criteria so it is, once again, promising to see that BABIP more-or-less remains steady during most of the aging years. We might need to expect a small drop between now and 2020, though it seems reasonable to expect Goldy to be able to maintain the ability to hit for a decent average in his 30s.
Putting it all together, we can see how this group’s overall offensive value fared through their selected years. As to be expected, the overall offense did go down, though it did stay at a fairly healthy level until the very late 30s. The biggest drop appears to happen early - between 28 - 31 and 32, primarily driven by the drop in BABIP.
Do note that this chart shows a lot of variation from year to year. So while the previous charts show that most of the hitting metrics tend to stay somewhat stable throughout the 30s, their overall consistency from one year to the next doesn’t.
Overall, these comps paint a fairly promising picture that Goldy can succeed as a hitter in his 30s. He plays a low stress position and has had virtually zero injury issues in his career. Combine that with the frequent reports that Goldy has a strong work ethic and keeps himself in good shape and he seems like a good candidate to sign an extension in his 30s and actually come out even or ahead.
Expectations probably need to be tempered a bit - Goldy will probably be closer to a 120-130 wRC+ hitter than the 140-160 wRC+ hitter that he is now - but this is probably better news than many people were expecting for Goldy’s potential aging.
Of course, only time will tell us for sure, but Goldy looks to be worthy of an extension from the Diamondbacks in 2020 and beyond.