“” Making the Sabermetric Argument for Increasing Fastball Velocity - Driveline Baseball

Making the Sabermetric Argument for Increasing Fastball Velocity

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Reading Time: 4 minutes

In talking with major league executives, I often tell them: “What would it be worth if you could restore the velocity of guys who are dropping off, or improve the velocity of organizational players?” They all respond with: “Oh, a lot. For sure.”

However, I never could get a dollar figure out of them, and I hadn’t done any research myself, so I decided to roll up my sleeves and do a little educated guesswork on my own. Here are the given variables for a starting pitcher in the major leagues (loosely based off a former pitcher in the last 5 years with middling/decreasing velocity who ended up out of baseball last year):

  • FIP Constant 3.12
  • Pitcher is a right-handed starter
  • Peripherals: 24 GS, 255 FB, 28 HR (11% HR/FB), 50 BB, 2 IBB, 7 HBP, 120 K (7.2 K/9), 150 IP (6.25 IP/start) – 5.02 FIP 
  • Park Factor = 100 (neutral)
  • League Average FIP = 4.80
  • Replacement Level Win% for Pitcher = 38%
  • 86 MPH average fastball velocity

This pitcher isn’t very good for MLB standards, posting a 5.02 Fielding Independent Pitching (FIP) stat. (For more information on FIP, check out the Fangraphs library.)

We’re going to assume he is sick of being bad at baseball since he’s being threatened with demotion to AAA if he doesn’t figure out how to produce better on the mound. He thinks about how he’s going to improve, and does some hard thinking. In the off-season, he finds someone who will work with him to restore his once-great fastball velocity to where it was in college – 90 MPH. Let’s say that this person’s program increases the pitcher’s average fastball velocity by 4 MPH, going from 86 MPH to 90 MPH heading into the season.

How Will His Peripherals Change?

Here are some educated guesses based on sources I’ve found on the Internet:

Now, remember, these studies aren’t perfect, but they’ll give us a baseline of improvements the pitcher can expect to see if his velocity improves. You can adjust them downwards or upwards based on your own thoughts/biases if you like.

We’ll hold his innings pitched and games started constant, even though if he got a lot better, he’d probably pitch more (and deeper into games). We’ll also hold his walks, hit batters, and intentionally walked batters constant. As such, here are his new peripherals:

24 GS, 230 FB, 24 HR (10.34% HR/FB), 50 BB, 2 IBB, 7 HBP, 141 K (8.464 K/9), 150 IP (6.25 IP/start) – 4.39 FIP

A 4.39 FIP is decent – it represents a 12.5% improvement from the year previous.

It’s About the Money

So we’ve calculated that this pitcher’s FIP would improve from 5.02 to 4.39, but what does that mean when it comes to how much money it’s worth to the parent organization?

Assuming that the league average FIP was 4.80, the pitcher’s Wins Above Replacement (WAR, using Fangraphs formula) for the first year would have been 1.476, meaning he was worth about 1.5 wins more than a replacement level (good/very good AAA but bad MLB) player. If you take a quick shortcut and say each WAR is worth $5 million, the player would have generated $7.38 million in revenue for the club. Not bad, since he’s close to the league average in FIP, but he’s been regressing and the club expects him to be worse, meaning his value will continue to drop.

However, with the player’s improvements in the off-season, his new WAR would be 2.683 – and using the same WAR valuation, this player would actually improve his value to the club to the tune of $13.42 million for his performance. This means that the club picked up an additional $6.04 million as a result of his fastball development in the off-season – and more than one WAR in the process, possibly putting them into the playoffs and generating more revenue that way.

(Raw data / calculations and formula can be found in the comments.)


What would it mean to a club to have two guys per year add 2-4 MPH on their fastball at the middle/higher levels of the game? I think this exercise shows how valuable a velocity development program inside the player development branch of an MLB club could be.

Comment section

  1. drivelinekyle -

    Pitcher X
    FIP Constant 3.12
    Pitcher is a right-handed starter
    Peripherals: 24 GS, 255 FB, 28 HR (11% HR/FB), 50 BB, 2 IBB, 7 HBP, 120 K (7.2 K/9), 150 IP (6.25 IP/start) – 5.02 FIP

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