Analyzing How the Cutter Has Impacted Offense in Major League Baseball

A couple years ago, the cut fastball was Mariano Rivera's pitch. He was the only pitcher in baseball who threw it with any regularity, not to mention with any real skill.

Now it seems like every pitcher in the majors features a cutter in his repertoire. The popularity of the cutter has increased dramatically, and hitters around the league aren't crazy about it.

"Your brain is telling you fastball," Torii Hunter told Sports Illustrated in 2011. "Then the ball breaks, and you're done."

"The cutter," Chipper Jones told ESPN's Buster Olney, also in 2011. "The bane of my existence."

"It's not a fun pitch at all," Corey Hart told MLB.com last year. "If a normal pitcher can throw that well, he becomes a really good pitcher. It's frustrating, because a lot of guys are throwing it now. It's another thing we don't want them to throw."

Based on testimonies such as these and the sudden popularity of the cutter, you'd think it was the ultimate pitch.

It just might be, for the statistics vouch for it as well. Observe...

Just How Popular Is the Cutter?

There have been numerous articles written over the last few years about the rising popularity of the cutter, and they don't exaggerate. The numbers testify that there are indeed more pitchers throwing cutters these days.

This is where the PITCHf/x system comes in handy. It's a tracking system that has been in every major league ballpark since 2007. It was designed to track everything anyone ever needs to know about pitches thrown in the majors: velocity, location, spin, break, you name it.

Now, the PITCHf/x system is not foolproof when it comes to tracking pitches. The system has gotten tweaks year after year, so it's not tracking pitches the same way now as it was in 2007. Even now, it's still possible for the system to mistake a four-seam or two-seam fastball for a cutter and vice versa.

The system is accurate enough, however, to show just how much cutters have caught on over the last couple of years, particularly among starting pitchers. Here's a look at how many starters (min. 150 innings pitched) have taken to throwing cutters more than 20 percent of the time since 2007.

Back in October of 2010, FanGraphs' Dave Cameron referred to the 2010 season as the "Year of the Cutter" when everyone else was calling it the "Year of the Pitcher." You can see why.

When the cutter first rose in popularity in 2010, it wasn't no-names who were making it popular. Among the notables at the top of the cutter charts that year were Dan Haren, Roy Halladay, Jon Lester and C.J. Wilson. Halladay's cutter helped him win the National League Cy Young Award.

Halladay may have been the one who started the rise of the cutter. PITCHf/x shows that he threw his cutter only 15.5 percent of the time in 2008, but then 27.4 percent of the time in 2009. He led the league in complete games and shutouts for a second straight year, and upped his strikeout-to-walk ratio from 5.28 to 5.94.

Between 2008 and 2009, Halladay won more games and pitched more innings than anyone, and his 2.78 ERA tied him for third-best among pitchers in that span with Johan Santana. Since he stood out as being the game's best pitcher, other hurlers may have chosen to follow his fine example by adopting the cutter.

But the cutter evolution hasn't been unique to starting pitchers. Relievers have gotten in on the fun as well. 

Here's a look at the rise of cutters among relievers (min. 50 innings pitched) since 2007.

From 2007 to 2009, Mariano Rivera was all on his own atop the cutter leaderboards. By 2010 and 2011, he was rubbing shoulders with pitchers like Octavio Dotel, Joakim Soria and Kenley Jansen (whose cutter is absolutely freakin' FILTHY).

They weren't necessarily stealing Rivera's thunder, but, well, they were clearly trying to.

Also of note: The rise of the cutter among starters has been a primarily right-handed revolution, but the trend is even more pronounced among relievers

That's not exactly a surprise, as there's a far greater chance of a right-handed reliever being brought in to face a left-handed hitter than there is of a left-handed reliever being brought in to face a right-handed hitter. The pressure is on righty relievers to have something to get left-handed hitters out.

And that's what the cutter is for, of course. A cutter thrown by a right-handed pitcher will break in on the fists of a left-handed hitter. He'll have a hard time laying off it, but a harder time making solid contact with it.

This has been Rivera's M.O. for years. Given his success, it's a wonder why it took so long for other pitchers to follow suit.

Since both of the tables above suggest that the rise of the cutter has been initiated by right-handed pitchers, a simple question arises: How are left-handed hitters being impacted?

Impact on Left-Handed Hitters

Give a right-handed pitcher a weapon with which he can attack left-handed hitters, and he'll use it with extreme prejudice. Especially if the left-handed hitter at the plate is a dangerous one.

Not so coincidentally, the league's top left-handed hitters have started seeing more and more cutters in recent years. Per PITCHf/x, here's how many cutters Joey Votto, Prince Fielder, David Ortiz, Josh Hamilton and Adrian Gonzalez—who top the charts among lefty hitters in OPS since 2007—have faced over the last five seasons:

Some of these lefties have handled the rise of the cutter better than the others. Votto, for example, slugged .583 against right-handers in 2009 and then .673 against right-handers in 2010. Hamilton slugged an absurd .716 against right-handers with more cutters coming his way in 2010.

On the other hand, Fielder went from slugging .610 against righties in 2009 to slugging .544 against righties in 2010. He slugged .579 against righties in 2012 while he was seeing more cutters than ever.

Of course, the cutter isn't popular among right-handed pitchers because it can be used only against elite lefty hitters. The cut fastball is a solid weapon against any left-handed hitter, and the league's left versus right splits since 2007 show that it's had the desired effect.

The consistency in the numbers put up by lefties against righties from 2007 to 2009 is uncanny. What's even more uncanny is how much the drop in production in 2010 stands out, and how the numbers have yet to go up again two seasons since.

A one-year drop in production? That's a fluke.

A two-year drop in production? That's a head-scratcher.

A three-year drop in production? That's a trend.

Meanwhile, there's the cutter rising in popularity primarily among right-handed pitchers. Chalk that up to coincidence at your own peril.

Is It Only Left-Handed Hitters Who Are Suffering?

I'll cut right to the chase with the answer: No. It's not.

As this table will show, offense in general is on a sharp decline in MLB.

Numbers via Baseball-Reference.com: Offense and Pitching.

Granted, there's more than one force at play here. As convenient as it would be to chalk the decline of hitting numbers solely to the rise of the cutter, it's not that simple.

Most notably, hitters aren't nearly as juiced up as they used to be, and for good reason. The release of the Mitchell Report in 2007 put players on notice that their secrets aren't exactly safe. In addition, the league's drug-testing has only gotten tougher. It's going to be even tougher going forward with new testing procedures for human growth hormone and testosterone now in place.

However, some due credit must be given to good pitching, as it's not like pitchers have descended into their own rut of mediocrity. On the contrary, they've enjoyed a renaissance.

When I spoke to Hall of Fame third baseman Mike Schmidt in July, he noted that pitching is more an art form now than it's ever been. Pitching coaches are "gurus" who are obsessed with "pitching theory," and even power pitchers have several secondary offspeed pitches to turn to nowadays. It's not just fastball/curveball or fastball/slider.

And then there's the cutter. It may not be solely responsible for the struggles of left-handed hitters and the decline of offense in the last few years, but the way in which its rise in popularity has coincided with these things speaks for itself.

For the league's hitters, the big concern shouldn't be that the cutter is working. The big concern should be that it's not going to go away until they prove they can hit it.

So far, no dice.

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