John Lackey, Tim Hudson and Pitching Longevity

Every year, there’s a gaggle of young guns, ready to take the league by storm. Wether it’s Clayton Kershaw, Jose Fernandez, or Matt Harvey, there’s a new face that everyone can dream careers upon. Unwrinkled faces, unworn arm ligaments, and the bright unknown future might be the stuff Spring Training dreams are built upon.

And here we are, October 14, 2014, and we’ll be watching 39-year-old Tim Hudson go up against 35-year-old John Lackey in game three of the National League Championship series. If, at the beginning of this decade, you had these guys down as top-25 pitchers for the next 14 years, congratulations. This game is your reward.

But that won’t stop us from looking back and trying to figure out how we got to this moment.

Tim Hudson’s career arc might be more traditional. He didn’t quite pine for the days when he had more velocity, but he did say “it’d be nice if I still had that 94-95 in the tank” during Monday’s NLCS workout day press conference. As he’s aged, he’s thrown more junk, as you can see from this Brooks Baseball chart:

Just a few weeks ago, Hudson admitted as much. “Where I’m at in my career, there’s nothing really overpowering, so I got to mix everything in there, throw it to the wall and see what sticks,” Hudson said then. “Throw the rosin bag out there a couple times.”

As natural as this progression feels — big velocity gives way to breakers and off-speed stuff in fastball counts — it isn’t something you can count on. I’ve found in the past that age only explains about 10% of the variance in fastball usage. There are other ways to age.

Like, take as a pertinent example, John Lackey’s pitching mix over time. Despite sounding like Hudson at the press conference Monday — “I throw a little bit of everything nowadays. If it feels good, I invent stuff on the mound” — Lackey’s gone to the fastball more often in the recent years. To the point where he’s almost back to the fastball usage of his first few years in the league.

Everyone finds their own mix as they age, and that’s probably why age alone doesn’t tell you everything about a pitchers’ fastball usage.

Maybe something Hudson said when asked about how he’s a different pitcher now can help us think about the longevity of pitchers: “I know my mechanics better now.” And Lackey said that the most important thing this time of year is “to think about the glove, think about location… and try to throw it through that thing.”

Both of these guys have excellent control, landing in the top twenty by walks per nine over the last two years. You don’t have to look far on the Giants team to see what can happen when age meets bad command, so it’s not busting brains to say that good control can make for long careers.

But it’s stark when seen this way: Since 2000, there have been 42 qualified starting pitchers that have pitched past 35 years old. Seven of them had walk rates that were worse than league average. As a group, the old pitchers over that time frame walked 6.6% of the batters they faced, and all qualified starters walked 7.7% of the batters they faced.

You might want to talk about survivor bias here. We’re only looking at the pitchers that survived, right? But couldn’t this be why they survived?

Here’s another way of looking at it. We know from our pitcher aging curves that walk rate is one of the most stable aspects of a pitcher’s performance over time. Perhaps it makes sense that the pitchers that last the longest are the ones that have the best command. They aren’t depending on velocity or strikeout rate, the two things that fall off the quickest.

Maybe we don’t need to figure it out for every pitcher. But since both John Lackey and Tim Hudson are around average or below in terms of strikeouts and velocity, it’s fair to look for something they have in common that has helped them age gracefully. Perhaps it’s that ability to throw their pitches for strikes that has led to this matchup today.