How Has Pitching Velocity Changed in Past Decade?

I was reading a few books on baseball from the 1970s and found it amusing how often a pitcher throwing 90 mph was a flamethrower and that mid 80s was considered sufficient.  Nowadays, success with those velocities would be considered highly improbable.  This left me wondering if our comprehensive measurements of mean fastball velocity since 2002 (from FanGraphs) could show any differences in the number of hard throwers in the past decade.

Starting Pitcher Velocity

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Pitchers throwing a mean fastball velocity above 90 mph has increased to 188% in 2011 compared to 2002.  Pitchers throwing harder than 94 mph has doubled over that same time period.  This growth in velocity at the Major League level occurred in 2007 and continues to increase.

Reasons I can think of for this occurring:

• Teams want their pitchers with higher velocity to pitch more often and refrain from converting them to relievers.
• Starters are being trained to pitch all out for shorter outings rather than trying to dialing down to last the entire game.
• More hard throwers are available.

  • Fastball velocity is being valued more and baseball is able to out recruit other sports for these prospects.

  • Teams are more willing to convert hard throwing outfielders, middle infielders, and catchers to pitching. 

A number of these ideas could be tested by merely making a similar graph seen above for relief pitchers.  If we also see an increase in the number of hard throwers in relief then we will know that the overall population of pitchers are throwing harder.  That would run contrary to the first two reasons and point toward the third one as valid.

Relief Pitcher Velocity

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We see a similar increase in velocity as we did with starters.  However, growth is slow and gradual from 2002 to 2008.  In 2009, velocity jumped up and plateaued.  Relief pitchers with a mean fastball velocity above 93 mph increased to 221% in 2011 over what was available in 2002.  Perhaps more amazingly, pitchers throwing on average more than 96 mph increased 1,200% from 2002 to 2011.  In 2002, only one pitcher average a fastball over 96 mph: Billy Wagner (97.6).  In 2011, eleven pitchers sat above 96 mph: Henry Rodriguez (98), Aroldis Chapman (97.9), Jordan Walden (97.6), Daniel Bard (97.3), Bobby Parnell (97.2), Joel Hanrahan (97.1), Brandon League (96.5), Neftali Feliz (96.3), Craig Kimbell (96.2), Jason Motte (96.0), and Jason Lindstrom (96.0).

Conclusion
The number of pitchers capable for throwing hard has increased over time.  It does not readily appear that hard throwing reliever are being converted to starting pitching as the increase is apparent in both groups.  This leaves me thinking that there are simply more hard throwing arms available.  This could be due to natural progression or it may be an element of pitching that is now being emphasized to  greater degree.  I have talked to a few scouts who angrily mention how pitching velocity is becoming valued too much because it is a quantitative measure on pitching prospects that cannot be embellished and that qualitative measures are being relied on to a lesser degree.  I am not so sure I believe that, but it is an explanation that should be floated out there.

My personal belief is that hard throwing arms are being more heavily sought after.  Teams are willing to pay extra to draft prospects who show plus velocity over pitchers who perform well due to a polished approach.  In an earlier post, I showed in an awfully noisy graph that a mile per hour in velocity saves half a run over the course of 100 fastballs.  That is the difference between a pitcher giving up 6 runs over 12 innings vs 5 runs over 12 innings.  In terms of ERA, that means a 4.50 ERA would decrease to 3.75 ERA.  Certainly more is involved than simply velocity, but it certainly is a trait of a pitcher that is quite important.  It may be that other teams simply are valuing this more and are better at finding and getting these arms to the majors.  In other words, perhaps more athletic players with live arms are giving more consideration on the mound than trying to make their skills work in the field.

Perhaps more likely, competition is simply rising in baseball.  As it pretty much always has.  Players get stronger and the training improves over time.