There is an adage in baseball that "sinkerball pitchers improve as the game goes", that in particular the sink improves - so sinkerball pitchers tend to give up a lot of fly balls in the first few innings but then get more sinking action later on, leading to sinkers actually sinking and yielding ground balls (or swing-and-miss). (I can't immediately find this online, but it's a common adage from sportscasters; Steve Stone just mentioned it during the White Sox - Twins game on 7/7/2021).

If this is true - and I'm open to statistics otherwise - why? If it's because being tired helps, why don't they just throw a few dozen extra pitches during warmup at full speed? If it's something else... what?

  • My general take on any of these "old adages" is that they're wrong until proven to be right! I guess it would be possible to do something like a comparison of sinkerball pitchers vs fastball pitchers the second/third time through the order, but that feels like a non-trivial research project.
    – Philip Kendall
    Jul 7, 2021 at 20:35
  • Yeah, I definitely was thinking along the same lines... what I'm more hoping for is someone who is an expert in baseball who understands "why" it would be that way (or at least the why that people think). (And I hope the answer isn't that the illegal grippy substances work better over time (as they're applied to balls and hands over and over again) … but I'm not sure it's not!) It does seem, anecdotally, to be fairly accurate - I remember Carlos Zambrano for example back in the day having a lot of tough 1st-2nd innings but better later on, while other pitchers are the reverse.
    – Joe
    Jul 7, 2021 at 20:52
  • I wonder if it has something to do with there being a greater difference between the sinker and the four-seam fastball early. A diminishing difference may make it easier to fool the batter later in the game. It's not so much that the sinker sinks less early, but that the batter has an easier time identifying it and adjusting appropriately.
    – chepner
    Jul 15, 2021 at 13:26

1 Answer 1


Well to be honest, a lot of sinkerballers would "doctor the ball" (adding foreign substances to the ball [Vaseline, spit]) to increase downward action. Baseballs that spin faster (spin backwards in particular) give the illusion of the ball "rising" (not physically possible if throwing overhand) because the back spin is helping it hold its plane longer than a ball with less spin, or ball with Vaseline. The sinkerballer is actually playing off of the opposite phenomenon (although sinkerballs do actually sink). It's all about deception and the more different pitches I've shown you the harder it will be to anticipate. (A sinker isn't a swing and miss pitch; it's to induce poor contact.)

  • "Well to be honest, alot of sinkerballers would "doctor the ball'" <- could you provide some links to reputable sites to support this statement?
    – Philip Kendall
    Jul 25, 2021 at 12:02
  • Here ya go : en.m.wikipedia.org/wiki/Spitball but since you seem like the type that feels wiki isnt reputable. pitcherlist.com/sink-or-spin-what-makes-sinkers-effective scroll to bottom for table showing less spin equals more vertical drop
    – Otot1029
    Jul 26, 2021 at 2:00
  • I understand the physics of the situation - do you have evidence that sinkerball pitchers do/did this significantly more than other pitchers?
    – Philip Kendall
    Jul 26, 2021 at 6:03
  • 2
    This doesn't even mention sinkers improving as the game progresses, much less explain why it occurs. Even if we accept the accuracy of the claims, they don't answer the question asked. Answers should at least address the question.
    – mdfst13
    Jul 26, 2021 at 6:14
  • Read my first post @mdfst13 answer is there?
    – Otot1029
    Jul 26, 2021 at 8:37

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