It cuts deep: The 'great tiebreaker pitch' changes MLB

Jake Arrieta announced his arrival as a solid major league starter this summer by taking no-hitters into the seventh inning of back-to-back games.

The report from a scout who had seen both games was clear:

"The others are minor league cutters compared to what Arrieta is throwing."

David Robertson has taken over as Yankees closer after an apprenticeship under Mariano Rivera, who turned the cutter – or cut fastball – into an unprecedented art form.

Part of that tutelage, or so the story goes, was learning the pitch.

"It's a slider," Arrieta insists.

"It's actually my fastball," says Robertson, informed enough about what made Rivera famous to understand that excellence may never be duplicated.

So, what is this mysterious, often misidentified, pitch whose use is increasing more than any other – nearly six-fold over the past decade, a period of time where the game's advantage has tilted from the mound to the batter's box?

"It's the great tiebreaker pitch," says Baltimore Orioles manager Buck Showalter. "The key is that it (looks like) a fastball for so long. It's a fastball until it's right there. It's so easy to say don't swing at it until you're in the box."

It's the horizontal version of the split-fingered fastball, another pitch that had its turn as the chic difference-maker in the major leagues, largely in the 1980s.

A little bit of movement – the very late movement Showalter describes after you've begun to swing – and you can't "barrel up."

That's the cutter-throwers' buzz word – barrel up, or hitting the ball with the thickest, most potent part of the bat. That's why Rivera, who threw the pitch more than 80% of the time, was being presented gifts made from broken bats on his farewell tour last year.

The cutter is so difficult to recognize we're not even sure how much it's being thrown.

Pittsburgh Pirates closer Mark Melancon says he throws it 85% of the time.

"It's made a big difference in my career," says Melancon, who learned the pitch from coach Billy Connors in the Yankees system but never got to the big league bullpen to trade secrets with Rivera.

Problem is, two of the game's most preeminent data analysts begged to differ - significantly - with his theory.

Fangraphs.com said Melancon was throwing his cutter 48% at the time; brooksbaseball.net said 64%.

If folks in the ballparks tracking the pitches have as much trouble with the cutter, imagine what it's like to try hitting it.

"That's the way the pitch started for me, to miss barrels, get weak contact early in counts," says Arrieta, whose 2.18 earned-run average in 15 starts is well below the 5.23 mark over four previous seasons when he started that many games.

Over his past nine starts, he's allowed 31 hits in 61 innings, striking out 71 and inducing 25% more ground balls than in the past.

But – cutter or slider?

The great debate

Former major league pitcher Jim Deshaies, who broadcasts all of Arrieta's games, laughs about the debate and recognition problems.

Fangraphs data suggests Arrieta threw the cutter 6.1% in 2013. This year: 28.1%.

"The cutter breaks across, the slider has more downward tilt," he says. "Often it's not even intentional; there's no grip change."

When the nuances become intentional and can be mastered, look out.

"I can change the movement on it," Arrieta says. "If I want to throw something high, up and in to a lefty, I can cut it under his hands, give it a little bit more lateral movement. A lot of times when I see it up on the board with the velocity and the pitch that it is, they do call it cutter. The good thing is that I can add and subtract velocity, so that makes the pitch even more effective."

And one more pertinent point:

"Same grip," Arrieta says. "Just basically my hand position at release point and that's basically what creates the rotation."

The rate at which the ball spins is crucial. The higher the spin rate, the more effective the pitch – and maybe the more risk of injury depending on what a pitcher must do to create the spin.

According to Fangraphs, cutters are still just 6.2% of all pitches thrown in the major leagues this season, up from last year's 5.8%.

Yet in 2004, it comprised just 1% of all major league pitches - when major league teams averaged 4.81 runs per game.

This year, that figure is 4.11 runs per game.

Most of the cutter's increase comes at the expense of the traditional fastball – down from 62.6% to 57.6% over the decade – but why isn't everyone doing it?

Don't try this at home

Start with Arrieta's last point about grip and creating rotation.

Robertson insists his cutting action merely comes naturally when he throws his fastball with the traditional four-seam grip. And he laughs at the urban legend that, because he succeeded Rivera as Yankees closer, the master also passed along the secret.

That would have required a hand transplant.

Rivera can touch his wrist with his fingers – yes, on the same hand.

Even his cutter was based on his four-seam grip - but he was able to use his long fingers and loose wrist to perfect and apply almost unmatchable pressure that made the ball break so late.

No unnatural twists of wrist and elbow translated into a 19-year career.

Trying to replicate that action becomes a combination of mystery, trepidation and even disaster.

"It hurts you," says the scout who watched Arrieta and who requested anonymity for competitive reasons. "Wear and tear on the elbow. You'll have a shorter career but you could get that one big payday."

Injury concerns can be a factor, though the American Sports Medicine Institute - which released a widely-cited position paper on causes of Tommy John surgery this year - says there's no direct link between injuries and the adult arm throwing breaking balls.

Still, trying to force the cutter into your repertoire worries some pitchers and coaches.

"Wear and tear, I think, is people who try to manipulate the ball," says Cleveland Indians reliever Bryan Shaw, now, per Fangraphs, the unofficial cutter king at 69.8% of his pitches since Rivera has retired. "That's more unnatural for your arm, whether it's twist your wrist or twist your elbow. Mine happened by accident so it's just the natural way my arm throws now. "

Shaw laughs now that he's turned into one of the game's emerging set-up men thanks to a bad-attitude cutter that dates to he and Wade Miley being sent to the instructional league while Arizona Diamondbacks farmhands.

"We didn't really take it seriously," says Shaw. "Playing catch every day, just flipping the ball to each other, instead of getting out on top and throwing through it, the angle of my hand slipped and the muscle memory just turned into that."

And the ball cut, similar to what Rivera says he stumbled on two decades ago.

"For me, it's just a normal four-seam grip like everybody else," Shaw says. "The way I throw it, it comes off my hand just a little bit cockeyed. Now, I try to throw it straight just messing around and I can't do it."

But the pitch doesn't become special for Shaw, Arrieta or anyone else until they can command it in any situation.

"The biggest key for me is being able to throw it to both sides of the plate," says Oakland's Jesse Chavez, having a breakout year in his 12th professional season, and a key reason why the Athletics survived a rash of arm injuries to produce baseball's best record.

"Any hitter in the big leagues sees it enough to be able to make the adjustment. It's all just timing, when you use it and where you use it."

That's why few starting pitchers are true cutter specialists.

'A bad cutter goes a long way'

Dan Haren of the Dodgers throws the most among starters, just under 40%, and he admits he uses the pitch's movement to make up for a gradual velocity loss over his career. Over the past five years, only now-retired Roy Halladay threw it more often among starters.

Kansas City's James Shields, a Halladay disciple, says he learned that location is as crucial as the movement.

"The reason Halladay was so successful was because he mixed up his pitches and mixed up his location," Shields says. "If you throw all of your pitches to both sides of the plate, it's double the pitches. I like to be an unpredictable pitcher. It's just another weapon for me to use in any count."

Brandon McCarthy is glad he has his weapon back. He's flourished in three starts since the Yankees acquired him from the Arizona Diamondbacks - producing a 1.45 ERA and 17 strikeouts in 18 2/3 innings.

Over 40 starts with the Diamondbacks, McCarthy had a 4.75 ERA - in part, he says, because the team discouraged him from throwing his cutter.

Cutter alarmists often cite the pitch's high-risk, high-reward factor. Executing it precisely is crucial.

"A bad cutter goes a long way," Showalter says, because without the late movement it just drifts across the middle of the plate.

The Orioles, in fact, deter their minor leaguers from developing the cutter, believing it's more productive to work on a slider or curve with more depth in its break.

"Some pitching coaches will tell you it takes away from the fastball," Showalter says. "Some will say if it's thrown properly, it doesn't matter. Some people say you twist it off sooner or do you hold on through it. Everybody has a theory."

Arrieta's theory is that it's a difference-maker in his career, not to mention the impact the pitch's increased use is having on major league hitters.

"Absolutely," he says. "I can throw it both sides of the plate. I can throw it up and in to a lefty, up and in to a righty, front door it, back door it. I can throw it to all four different parts of the strike zone."

When done correctly, it all seems so simple.

"All you're trying to do is take guys off the sweet part of the bat," says Showalter. "That's why it's so attractive to people. The guy in New York, Rivera, he was a freak."

Contributing: Jorge L. Ortiz