By having its pitchers throw fewer fastballs and rely more on breaking pitches, New York is trying something that might seem radical but could become the future of the sport.

Was that the future of pitching that the Yankees displayed at Fenway Park last weekend? And what do they know that the Pirates, Mets, Twins and Orioles don’t know? The answers are shocking to anybody remotely familiar with pitching maxims over the past 100 years.

Let’s start with this: The Yankees went into Fenway Park and thoroughly throttled Boston's deep lineup in its tiny ballpark. New York's pitchers posted a 1.76 ERA over four games. The Yankees split the series, though they should have taken three of four, but for a meltdown by closer Aroldis Chapman in the ninth inning of the opener.

Here’s the cutting edge part: New York's pitchers threw only 40.7% fastballs in the series. (Fastballs here are defined as four-seam and two-seam fastballs, not cut fastballs.)

For the Yankees, this was not an anomaly. They throw the fewest fastballs in baseball, and it’s not even close. They average a fastball rate of just 43.1%. Houston is next lowest at 47.3%.

What makes New York's low fastball usage all the more surprising is that its pitchers have the highest average velocity of any team in baseball (94.3 mph, tied with Pittsburgh).

Time out.

Take a minute to let that sink in: The Yankees have the most velocity in baseball, and yet they throw the fewest fastballs in baseball.

What in the name of Randy Johnson, Nolan Ryan, Bob Feller, Walter Johnson and Bullet Joe Bush is going on here? Every generation has passed on to the next the importance of the fastball, old number one.

Pitch off your fastball ... Establish your fastball ... Change speeds off your fastball ... Sliders, curve and changeups are your secondary stuff…

That kind of thinking has been the bedrock of pitching.

No more.

And it’s not just the Yankees. Two years ago, no team in baseball threw less than 50% fastballs. Last year two teams threw fastballs a minority of the time: the trend-setting Yankees and Astros. This year five teams are throwing less than 50% fastballs: the Yankees, Astros, Angels, Indians and Rays—all contenders.

So I asked New York's pitching guru, coach Larry Rothschild, to explain this new world of pitching.

“Fastballs get hit,” Rothschild said. “It’s amazing to me to see guys throwing in the upper 90s and they get hit. I don’t know how these guys do it. That’s how good major league hitters are. They have adjusted to velocity. To hit upper 90s, you have to gear up for upper 90s. So hitters are going up there to gear up for velocity. And when they do that, they can hit it no matter how hard you throw.

“The other thing is fastball command. If you don’t have great command with your fastball, these hitters are so good they’re going to hit it. Not every pitcher has great fastball command.”

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The best fallout about the analytics era is that it challenges conventional thinking, such as the value of a stolen base attempt or the bunt. You can add pitch selection to this re-training of baseball minds. An old pitching coach might blurt out, “Establish your fastball, son.” But you look at these numbers—2017 batting average by pitch type, according to Statcast—and you tell me what it might do to your pitch selection:

Fastball: .274

Cut Fastball: .254

Changeup: .243

Curveball: .220

Slider: .218

If you want to separate four- and two-seam fastballs, the news is even grimmer for sinkerball pitchers: batters hit .295 against two-seamers. The postmodern swing, geared for optimum launch angles and high velocity, is making the low fastball ripe for hitting. Of the 10 pitchers with the lowest ERA this year, none of them throw sinkers as much as one-third of the time.

Based on the chart above, guess what pitch the Yankees lead the majors in? That’s right: sliders, which they throw 25.5% of the time. No other team is close. (The Padres are second at 23.6 and the Astros are third at 20.4.)

So why not throw even more sliders and even fewer fastballs? There is a point of diminishing returns. Breaking pitches, especially sliders, traffic in deception. They look like fastballs out of the hand. When you upset the balance too much—too many breaking balls and too few fastballs—you lose the effect of deception.

What the Yankees are doing is re-setting where that traditional balance point is. They are establishing that you don’t have to throw your fastball even half the time, a thought that would have shocked people in every other period in the game’s history. Right there with New York in this new-age thinking are five other heavily analytical-based clubs: the Angels, Astros, Dodgers, Indians and Rays (fastball use is higher in the NL because of pitchers batting; Los Angeles throws the fewest fastballs in that league, at 51.5%.)

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In the series in Boston, New York’s starters threw only 31.5% fastballs. Its relievers threw 55.2% fastballs, a number inflated by Chapman’s meltdown, when all 23 pitches he threw were heaters.

(It was eerily reminiscent of Chapman’s blown save in Game 7 of last year's World Series. As I revealed in my book, The Cubs Way, The Zen of Building the Best Team in Baseball and Breaking the Curse, the game-tying home run Chapman gave up to Cleveland's Rajai Davis in the eighth inning came on the 44th consecutive fastball he threw with David Ross behind the plate that postseason.)

There is no such thing as a fastball count against New York’s starting pitchers. They are likely to throw sliders, changeups or cutters on 2-and-0 and 3-and-1 counts. The Red Sox kept sitting on fastballs, but they just weren’t coming.

If the Yankees are new school when it comes to fastball usage, which teams are old school? I sought to find teams who stick to a traditional high percentage of fastballs, even though their fastballs get hit. Here they are, the only teams that rank in the top 10 in most fastballs thrown, but in the bottom 10 in batting average against fastballs:

Team percentage rank baA rank Pirates 63.3% 1st .283 T-23rd Mets 58.8% T-5th .284 24th Twins 58.0% 7th .293 27th Orioles 57.7% 9th .298 29th

It doesn’t make sense to be throwing so many fastballs when they get hit so much. These teams are proving there is such a thing as too many fastballs.

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The Yankees must be doing something right. Their rotation includes two young pitchers who never have pitched a full season in the big leagues (Luis Severino and Jordan Montgomery), a veteran pitcher who has become a cutter machine after losing his fastball (CC Sabathia), another veteran who has cut back on his fastball usage (Masahiro Tanaka, who is down to using the pitch just 32% of the time), and various replacements to come for Michael Pineda (who needs Tommy John surgery after he blew out his elbow after throwing more sliders than any pitcher except Tampa Bay's Chris Archer).

But somehow the Yankees have the third-best ERA in the AL, behind only the Red Sox and the Indians, and they’ve issued the third fewest walks. Moreover, the two pitching staffs in the league that are the most difficult to hit (.233, .238) are the two teams that throw the fewest fastballs: the Astros and Yankees.

New York has found a way to maximize what on paper looks like a rather ordinary staff. With so few fastballs, that way is something we’ve never quite seen before.