On Jon Lester, Ted Lyons, and pitching on six days rest

On Monday Jon Lester pitched by far his best game of the season—7 shutout innings, allowing 6 hits and no walks, while striking out 7. Due to the All-Star break, he was also pitching on eight days rest.

I decided to check Lester’s splits for pitching on days rest. Here are his splits for 2019 through 2021:

That’s a pretty dramatic set of numbers! In 10 starts on six or more days rest, Lester looks like a Cy Young contender. In 19 starts on five days rest, he’s about a league average pitcher. And in 28 starts on four days rest, he doesn’t look like he belongs on a major league staff.

Could this just be random (luck)? Well one set of numbers does give me pause—his strikeout numbers are actually lower with more rest. That suggests that balls in play are a pretty important factor, and we know that we should always assume that hits on balls in play are mostly random. But his walks and home runs are much lower with 6+ days of rest, which suggests that it’s not entirely balls in play.

Now let me tell the story of Ted Lyons, who pitched for the Chicago White Sox from 1923 to 1946. With a 260–230 career record and 118 career ERA+, he has sometimes been criticized as a weak Hall of Famer, though I think he was ultimately deserving of the honor. What’s always been interesting to me is his notable improvement late in his career 

From 1935 to 1938 (ages 34 to 37) Lyons was a good pitcher. His 3.98 ERA for those years was from a high scoring league, so his ERA+ was a very respectable 122. But from 1939 to to 1942 (ages 38 through 41), Lyons reached a new level. His ERA fell to 2.96, his ERA+ rose to 143, and his record was 52–30. During those years he won the ERA title one season, had the league’s lowest walk rate for three seasons, the best strikeout/walk ratio in two seasons, led the league in shutouts one season, and led the league in FIP and WHIP for one season each (not that anyone would have known what those meant in 1939).  I don’t think he would have made the Hall of Fame without his late career surge in performance.

What makes that even more interesting is that during those last four seasons, Lyons was used mostly as a “Sunday pitcher.” That is, most of his starts were made on Sundays, pitching on six days rest. The longer rest seems to have rejuvenated his career. In his Historical Baseball Abstract, Bill James wrote “I still think the use of an older pitcher on a regular once-a-week basis makes all the sense in the world. If you’ve got a pitcher who knows enough to get by without beating himself, if you give him a couple of extra days to come back from the last outing and get ready for the next one, there’s no reason he shouldn’t be able to give you fifteen good outings out of twenty starts.”

Is this a schedule that would work for Lester? Of course, if the Nats were to move Lester to a once-a-week schedule, they would need an occasional sixth starter. But guess what? When Stephen Strasburg and/or Joe Ross come back, the Nationals will have five or even six starters (if you count Paolo Espino, which I would) all of whom have been pitching better than Lester. I think they should try moving Lester to a once-a-week schedule and see if his performance improves. There doesn’t seem much to lose.

While I do favor trying Lester on a once-a-week schedule, I wouldn’t have his regular start come on Sundays. Back in 2012 when we were hoping that the Nats could keep Strasburg in the rotation long enough for the post-season, I recommended that he pitch once-a-week on Fridays. But well-known baseball blogger Tangotiger examined the options and found that Saturdays would work best in terms of causing the least disruption to the scheduled starts of the other pitchers in the rotation.

I’d love to see if Lester could revive his career as a “Saturday pitcher.”