Should Byron Buxton Fear the Swing Speed Aging Curve?

[Jamie Cameron]

A new blog post from Tom Tango illustrated that bat speed falls precipitously after age 31. Does 31-year-old Byron Buxton have anything to worry about? Let's dig in.

Image courtesy of © Matt Blewett-Imagn Images

We’re a full year into bat speed metrics being publicly available via Baseball Savant. Prior to a second full year of data, now seems like a logical time to take stock of what to expect from Twins hitters in 2025.

Recently, MLB’s Tom Tango released a blog post describing the relationship between aging and bat speed. While this is grounded in only one full season of data, there are some cromulent TwinsCentric conclusions to draw that may be relevant in 2025.

Here’s the headline: between ages 22-31, bat the aging curve of bat speed is very flat (dropping ~0.02 mph per year). From age 31 onwards, it decreases sharply (0.31 mph per year). Which Twin just turned 31? Byron Buxton. How could his bat speed be impacted by his age? In turn, could his overall offensive production be hurt by an age-related decrease in bat speed? Let’s dig in.

Before getting player specific, let’s reground in some league-wide bat speed context. League average bat speed is 72 mph. ‘A fast swing’ is 75 mph. Why is the 75 mph threshold important? 75 mph of swing speed is where you see per-swing offensive production reach league average. The drop off in per-swing production below 75 mph is considerable. In other words, swing hard, ball go far.

How does Byron Buxton fit into all these bat speed metrics? Pretty dang well, thank you very much. Buxton ranked third on the Twins in average swing speed (74.3 mph), coming in only behind Carlos Correa (74.5 mph) and Matt Wallner, who is in a league of his own (77.3 mph). How about fast swing rate? Same story. Buxton ranked third on the Twins, with 41.8% of his swings exceeding the 75 mph threshold (league average 22.6%). Place that in league wide context, and Buxton looks good, ranking 43rd out of 268 major league hitters in fast swing rate (minimum 500 swings in 2024).

If a typical player loses about 1 mph of bat speed every three years after age 31, we might look at Buxton’s average swing speed (2.3 mph above league average) and make the argument that this is an open and shut case of something we shouldn’t be too worried about. Buxton has some cushion with how fast his swing is, sure, but is there anything else to consider here?

As is the case with most baseball questions, the answer is, ‘maybe’? Let’s throw some other variables in the mix. Starting with a visual of where Buxton does the majority of his damage.

We can see that Buxton squares up the majority of his batted balls on pitches on the outer third of the plate. It’s also worth noting Buxton’s swing length, here. At 8.1 feet, it’s a long swing, significantly longer than league average (7.3 feet). It’s worth wondering what the impact of declining bat speed would be for Buxton, given the context of a long swing which thrives on the outer third of the plate? Buxton is also a hitter whose swing is rather stiff and whose output heavily relies on power, so is it possible the swing speed aging curve impacts a profile like his more acutely than a player with a more balanced offensive profile?

Given Buxton’s swing speed and fast swing percentage cushion (compared to league average), it seems unlikely his offensive production is in immediate danger. Still, Buxton will be an interesting profile to track as he ages given his combination of swing length, the part of the plate he does damage in, and the lack of malleability of his swing.

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[Mark G]

Does launch angle have anything to do with bat speed?  There are times it appears almost like a golf swing; is it easier and/or faster to swing upward as opposed to a flatter swing?  I am curious if that plays a role or not.  

[Old Crow]

They tell me launch angle is inversely proportional to bat speed.  

[rv78]

Just the other day I thought.......... It has been a while since we had an article about the great Byron Buxton. Bingo!

No worries with Bat Speed for Buck. It means nothing when you are injured....... which is the majority of the time. Next article please........

[Trov]

I am less worried about his bat speed, although this info does point why age 30 to 31 is really when guys start to drop off a ton in production.  I am more worried about his drop in run speed, which was a big reason why he was so good, when he could actually play.  

[Twodogs]

40 minutes ago, Trov said:

I am less worried about his bat speed, although this info does point why age 30 to 31 is really when guys start to drop off a ton in production.  I am more worried about his drop in run speed, which was a big reason why he was so good, when he could actually play.  

Why do some guys get better after the age of 31?  I mean like Nelson Cruz's best years were between the ages of 33 - 38?  His numbers looked good at 39 also but that was the short season so who really knows with that season?  But it was pretty obvious that his ability to field went down, but really seems like his ability to hit actually went up?  How does that happen if everyone drops off after the age of 31?  I mean he didn't just maintain for those extra 4 - 5 seasons he really seemed to get better?

[old nurse]

Yup, bat speeds slow down with age. The findings presented say on average. What makes Buxton average?  His bat speed already says he is not an average player so why should he e following a standard aging curve 

[Parker Hageman]

2 hours ago, Mark G said:

Does launch angle have anything to do with bat speed?  There are times it appears almost like a golf swing; is it easier and/or faster to swing upward as opposed to a flatter swing?  I am curious if that plays a role or not.  

This is one of the areas of data that I am very excited for people smarter than me to dig into. 

Right now, there is not a direct correlation between bat speed and launch angle. One stat that is not available publicly is Vertical Attack Angle (not to be confused with VAA on the pitching side) and that is a measurement of the bat angle through the zone. 

Think of this like the old Ted Williams bat path graphic. Zero degrees is flat. Positive is the upstroke and negative down through the zone. This metric correlates strongly to launch angle.

We haven't had too many in-depth studies using MLB's bat speed data (at least, not that I am currently aware of) but Driveline's internal study in 2022 suggests that there isn't a relationship between the attack angles and bat speed (although you could contend that an individual's optimal swing would have a higher bat speed based on one path or the other based on how they move, specifically). 

The other element that needs more parsing is location and pitch type, which dictates a lot of the swing path. 

I think the better hitters know their zones extremely well and hit those pitches hard. Then there are hitters like Arraez and Kwan who can cover more of the zone and pitch types because they don't sell out for bat speed (both had the lowest average bat speed in MLB last year). On the other end of the spectrum you have Stanton who is going to swing hard at everything, nuke anything he touches, and miss a ton of pitches as well. 

How this pertains to player development, ultimately, is that most orgs will choose to build the engine to swing hard and fast with some positive attack angle resulting in more optimal contact (sweet spot%). The next layer they want to teach is swing decisions, which, as this interview with Dillon Lawson at Fangraphs shows, is a very big piece of the training puzzle. If a player can conquer both, watch out. 

Sorry for hijacking the Byron Buxton comment section. Go Buck. Go Twins. 

 

[rusty boots]

1 hour ago, Twodogs said:

Why do some guys get better after the age of 31?  I mean like Nelson Cruz's best years were between the ages of 33 - 38?  His numbers looked good at 39 also but that was the short season so who really knows with that season?  But it was pretty obvious that his ability to field went down, but really seems like his ability to hit actually went up?  How does that happen if everyone drops off after the age of 31?  I mean he didn't just maintain for those extra 4 - 5 seasons he really seemed to get better?

hmmmm... let me take a stab at this one. Sterroids maybe? 

[terrydactyls]

I don't trust any "data" presented by a guy named Tom Tango.  Sounds like a porn star.  😇😇

[Blyleven2011]

Bat speed means nothing to me   , put the bat barrel to the ball and hit  ...

Gibson comes to mind in the 88 world series , injured but pinch hitting  he lofts  a homerun to win the game off eckersley  , it was just a weak swing but squared up the ball and presto , a homerun and lasorda was a happy camper ...

I've seen many players hit one handed  and get a hit , a players goal is to hit , a single , double , triple and a occasional homerun  ...

[NYCTK]

I'm putting the over under on career WAR left in his career at 6.0. Really not excited to see the rest of the career of a man whose value is derived from speed and power get dramatically slower and weaker.

IMO Twins would have been wise to shop him this offseason before he truly becomes a 4th OF, which he's arguably been since 2017 anyways. 

But this is from someone that doesn't believe in this team at all. If you actually think they have a real chance at 90-95 wins in 2025, it makes a move like that stupid as hell. 

[killertwinfan]

Buxton should fear this as well as swinging at too many pitches out of the strike zone. 

[Coach Wheels]

Let's just get Byron to play 130 games, then we can talk bat speed.

Here's a fact I've researched with Byron a lot. When he's hurt, his bat speed is 0.00 mph

[RpR]

Should Byron Buxton Fear the Swing Speed Aging Curve?

No.

[Schmoeman5]

Don't fear the reaper, and certainly don't fear the swing speed aging curve. 

[Aerodeliria]

Healing speed is far more important but definitely gets slower....

[Twodogs]

13 hours ago, rusty boots said:

hmmmm... let me take a stab at this one. Sterroids maybe? 

I know he got busted when he was younger, but his numbers weren't as good back then?  I'd think after someone was caught once, that they wouldn't want to get caught a second time as that is almost the death penalty.  

[Twodogs]

12 hours ago, NYCTK said:

I'm putting the over under on career WAR left in his career at 6.0. Really not excited to see the rest of the career of a man whose value is derived from speed and power get dramatically slower and weaker.

IMO Twins would have been wise to shop him this offseason before he truly becomes a 4th OF, which he's arguably been since 2017 anyways. 

But this is from someone that doesn't believe in this team at all. If you actually think they have a real chance at 90-95 wins in 2025, it makes a move like that stupid as hell. 

I would take the over on career war left in him.

[bean5302]

Not at all concerned about Buxton's swing speed. Buxton's Full NTC drops off after the a32, (2026) season. In the model above a32 lines right up with a28 with a drop off after that.

Regarding launch angles vs. swing speeds, I wouldn't expect a correlation. From what I can see, the faster the swing speed, the less likely a ball is to be squared up by the batter, in general. That said, the faster the swing speed, the higher the expected exit velocity when making contact so even non-ideal contact is more likely to result in a hit. At least, that's what I'd expect.

The swing path is going to be determine most of launch angle IMHO.