Maybe it began with the first prominent public presentation of the radar reading, that now-ubiquitous scoreboard and television screen standard that satisfies our need to know and overwhelms the art of estimation. A generation of kids saw mph scrutinized and monetized, and now they are bringing the heat to the bigs and altering the average.
And the game itself.
Velocity has changed, and so has baseball. The way it is scouted, the way it is discussed, the way it is managed.
"It has changed the benchmark," said Indians president Chris Antonetti, whose club had the fifth-highest average fastball velocity in the Majors last season. "I don't think you have to have a certain velocity to be successful, but the average velocity has picked up and raised the standard for everybody."
Fittingly, it is rising in a hurry.
Maybe 2008 doesn't feel all that long ago to you, but it was a much different time in baseball. The average fastball velocity that season was 90.47 mph. Last year, it was more than one mph faster. The percentage of total pitches registering 95 mph or more was 4.82 back in '08, compared to 9.14 percent last season.
And for the record, it's not just fastballs coming in faster. The average slider velocity went from 82.86 mph in 2008 to 84.24 in '15, and the average curve velocity went from 75.89 to 78.23 in that same span.
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Any evaluator will tell you that velocity, in and of itself, is not what makes a Major League pitcher.
"The most important thing is being able to pitch, and making pitches and commanding your fastball," Royals general manager Dayton Moore said. "These guys are in the Major Leagues because they can hit a fastball."
But there's no denying that faster fastballs have played a vital role in the ongoing rise in strikeout rates. In each of the past eight Major League seasons, a new all-time league-wide strikeout-rate mark has been set.
Looking solely at fastballs (four-seam, two-seam, cutter, splitter and sinker) that hitters offered at least season, the following percentage ended up as swinging strikes:
95 mph or more: 18.8 percent
94 or less: 8.2 percent
So, yes, there is something to be said for the concept of blowing "that speedball by ya." Velocity is impacting those K rates in a profound way.
The increase in average velocity and its impact on strikeout rates and offensive averages has been a talking point in the game for several seasons now. But that single-season jump in pitches 95-plus from 2014 to '15 was especially, um, striking.
"It's unbelievable the number of guys who throw 95," Yankees lefty CC Sabathia said. "You've got [a lefty relieving a lefty] and both of them throwing 95. It wasn't like that when I first came up."
Sabathia brings up a key point, because the impact of the uptick is most potent in the 'pen.
The bullpen factor
Time was, a kid with a live arm came up as a starter until positively proven otherwise. But teams are no longer afraid to develop pitchers as relievers at nascent stages of their professional career, because of the increasing emphasis on the importance of a bullish bullpen. And more than ever, it is sensible to build a pitching staff from back to front.
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Not having an army of relievers equipped with mid-90s heat is something of a competitive disadvantage, as the Astros -- who had the lowest average fastball velocity (91.2) of any relief unit last season -- acknowledged in sending a huge package to the Phillies for the fireballing closer Ken Giles.
"It's a balance," manager A.J. Hinch said. "You want to have different options, different ways to attack hitters, because some guys handle velocity and some don't. We didn't want to go to the other spectrum of having only velocity. But we did want to have a blend to maximize outs."
The average fastball velocity just from relievers has risen from 91.6 in 2008 to 93.2 last year. And though, as Hinch's point about balance makes clear, velocity is not the sole factor that determines a reliever's success, it is certainly shaping the way the modern-day 'pen is employed. Relievers are called upon earlier and more often. Last year's average of 5.8 innings per start was actually the fewest since '08.
"Even the best guys are going less than seven innings," Braves president of baseball operations John Hart said. "Look at No. 1 starters."
So we did. Taking each team's leader in adjusted ERA among starters who posted at least 150 innings for a single team, the average innings per start last season was just 6.3.
Certainly, every club would love to have two workhorses, as the Dodgers did with Clayton Kershaw (232 2/3 innings) and Zack Greinke (222 2/3), but that's just not realistic. Even the supposed best starters on each staff weren't consistently delivering seven innings before handing it off to the 'pen.
"Are teams trying to save the guys [via pitch count] a little bit? Maybe," Hart said. "But they also have so much confidence in what they're bringing in behind those starters. You don't have to finish the game, because you've got a guy throwing 96, 98, 99 coming in right behind you."
The average number of relievers used per team per game has climbed 10.8 percent -- from 3.71 to 4.11 -- just in the past 10 seasons. And this approach is clearly working, because bullpens are locking down leads. The percentage of games in which the team leading after three innings went on to win the game rose from 73.8 in '13 to 76.5 in '14 to 76.8 in '15.
The other issue looming over all of this is the effect of velocity on run scoring. With the rise in mph, we've generally seen a dip in scoring. Here are the average runs per game for each team since 2008:
However, we did see a slight uptick in run production last year -- the jump from 4.07 to 4.25 runs per game was the largest in a decade -- so perhaps that's a slight indication of batters adjusting to the velocity increase.
"I think you're going to see the other side of it," retired reliever Jeremy Affeldt said. "I think you're going to see the bat speeds increase, because now, all of a sudden, that 97 is not as hard as it used to be, because you're seeing it a lot. Hitters adapt to the straight fastball. It's the pitches where they can't stay back enough [that are problematic]. So I think you're going to see hitters adapt, and then you're going to see more guys throw below the average [velocity] to get more outs."
Maybe, for that reason, the average is bound to come down at some point. But in the meantime, those radar readings are headed in one distinct direction. Now more than ever, the heat is on.
Anthony Castrovince is a reporter for MLB.com. Read his columns and follow him on Twitter at @Castrovince.