Are No. 4 Starters Still Useful In The MLB Postseason?

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Chris Bassitt (Photo by Vaughn Ridley/Getty Images)

As MLB heads to the World Series, I canâ€t help but spend a moment thinking about the plight of an old baseball mainstay—the durable No. 4 starter.

From April to September, teams need these reliable rotation options to soak up innings with ERAs and FIPs that hover around league average. Without them, bullpens implode, and the season gets very long.

But then October arrives, and they disappear. Teams need their No. 4 starters to get to the playoffs, yes. But it appears teams have very much decided they are best off not using them when the postseason actually arrives.

Is there any position more valuable during the regular season and less relevant in October?

Over the past eight seasons, Chris Bassitt has been a paragon of durability and effectiveness. The 36-year-old righthander was once again an extremely effective No. 4 starter this year for the Blue Jays, going 11-9, 3.96 in 31 starts this year. His ERA+ was 108. His FIP was a perfectly respectable 4.01.

Successful teams need players like Bassitt. He threw 170.1 innings this season, marking the fourth-straight year he’s topped the 170-inning threshold. Heâ€s made at least 25 starts in every full-length season since 2019. Heâ€s durable and effective, as his 83-65, 3.64 career record in 1,278.2 innings illustrates. Heâ€s been worth every penny of the three-year, $63 million contract the Blue Jays signed him to in 2023.

But now that the postseason is here, heâ€s someone the Blue Jays have used very rarely.

Bassitt did get his moment in the sun on Monday, as he threw a scoreless eighth inning to help the Blue Jays finish off the Mariners in Game 7. It was only his second appearance of the postseason. He had previously been left off Toronto’s ALDS roster and then added back for the ALCS. After finishing second on the team in innings pitched during the regular season, heâ€s thrown just 2.2 innings in the playoffs.

Bassitt was vital for the Blue Jays in getting to October, but now that the do-or-die games are here, heâ€s been largely sidelined while rookie Trey Yesavage has stepped up.

Heâ€s not alone. Will Warren threw the third-most innings for the Yankees this season, but he made only one (rough) appearance for them in the postseason. Taijuan Walker, meanwhile, made 21 starts for the Phillies during the regular season followed by just one two-out appearance in the playoffs.

This used to be the world of the No. 5 starter. In the past, fifth starters would serve reliably all season and then get shuffled to a very modest role come the postseason. But nowadays, teams bounce around between using fifth starters and bullpen games if they aren’t happy with their back-of-the-rotation options. And so, it’s the fourth starter whose role has begun to diminish further.

Even the Dodgers aren’t immune to this. Los Angeles has four front-of-the-rotation starters dominating in the postseason this year. It would be crazy to suggest that any of Blake Snell, Tyler Glasnow, Yoshinobu Yamamoto or Shohei Ohtani fits the description of a No. 4 starter.

But that doesnâ€t mean the Dodgers didnâ€t value back-of-the-rotation starters. After all, those were the types of pitchers who dragged the team through the first four months of the season to allow these aces to thrive in October.

Consider that Yamamoto is the only Dodgers starter this postseason who threw more than 100 innings during the regular season. Less than 50% of the Dodgers’ regular season innings from starting pitchers came from their “Big 4” starters. In October, those four and their largely fresh arms have thrown 73.2% of the Dodgers’ total innings.

By having a first wave of arms to eat innings during the regular season, the Dodgers were able to patiently bide their time until Snell, Ohtani and Glasnow worked into postseason form.

In the final year of his illustrious MLB career, Dodgers lefthander Clayton Kershaw fits this description of a very useful starter who gets sidelined come October. Kershaw was excellent this year, going 11-2, 3.36 (124 ERA+) in 112.2 innings. But he also did not miss many bats. So far, he’s made one postseason relief appearance, giving up five runs (four earned) in two innings against the Phillies. He was on the NLCS roster but didn’t pitch in the series.Â

In trying to find a reasonably consistent thread that ties these decisions together, the clearest explanation is the increased emphasis on velocity in the postseason. During the regular season, the average fastball velocity across the major leagues was 94.3 mph. In the postseason, thatâ€s jumped to 95.8.

The difference in starter velocity is even more dramatic. During the regular season, starting pitchers averaged 93.9 mph with their fastballs. In the postseason, thatâ€s jumped to 95.7 mph—right in line with the bullpen velocity in the postseason.

Excluding openers, there have been 10 true starters this postseason who have averaged less than 94 mph with their fastballs. Those starters have posted a 5.59 ERA and 67 hits allowed in 56.1 innings with a 3.2 BB/9 and 9.4 K/9.

On the other hand, there are 13 true starters this postseason who have averaged 96+ mph with their fastballs. As a group, they’ve posted a 2.63 ERA and just 99 hits allowed in 143.2 innings with a 2.3 BB/9 and 11.3 K/9.

Come the postseason, teams generally want to turn to starters who can miss a lot of bats. Durable consistency is less in demand.

This was perfectly illustrated in Game 4 of the NLCS, which will forever be known as the “Shohei Ohtani Game.” When he wasn’t busy launching three home runs, the Dodgers sent Ohtani to the mound and watched him allow only two hits and three walks over six scoreless innings. He touched 100 mph while striking out 10 of the 22 batters he faced.

On the other side, the Brewers turned to Jose Quintana. Like Bassitt, Quintana is a wonderfully durable and effective starter who has thrown over 2,100 innings in his MLB career. He went 11-7, 3.96 (105 ERA+) in the regular season. But his Game 4 start was only his second appearance of the postseason (he threw three scoreless innings in relief against the Cubs on Oct. 8).

In Game 4, Quintana gave up a home run to Ohtani and two additional runs in the first. He exited after allowing three runs, six hits and a walk in two rough innings of work. In 2024, he had also been roughed up by the Dodgers in an NLCS start, allowing five runs in 3.1 innings, thanks again in part to an Ohtani home run.

Quintana likely will be a free agent again this offseason, as his current $2 million deal has a $15 million mutual option for 2026 with a $2 million buyout. And he will likely be in demand once again as a lefthander who can provide durable, consistent innings as a back-of-the-rotation starter. So, too, will Bassitt, who is also a pending free agent.

Just donâ€t expect to see them get much use next October.

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