Mo Chases For Mo

When the Yankees signed Mariano Rivera out of Panama back in 1990, George H.W. Bush was president, parachute pants were still kinda cool and no one had ever heard of an iPad. Yet, despite his 41 years, there's nothing dated about Mo. The cutter king has a 48-to-5 K-to-BB ratio in 51 innings, and his 2.5 Wins Above Replacement put him in the top 10 among MLB relievers yet again.

Rivera did leave Boston's Jarrod Saltalamacchia with a nasty bruise on his forearm last night, but he hasn't walked a hitter since July 3 and his 0.9 BB/9 is the second-lowest mark of his illustrious career. The Sandman has a sub-one walk rate because he's luring hitters to chase his cutter and occasional fastball off the plate at the highest rate of any reliever in the game.

Batters are chasing about 43 percent of Rivera's out-of-zone pitches this season, his highest clip dating back to 2008. Rivera loves to bust left-handers inside and pitches right-handers away with the cutter, often placing it out of the zone but just close enough to the plate that hitters feel compelled to swing:

 Frequency of Rivera's cutter location vs. lefties, 2011

 Frequency of Rivera's cutter location vs. righties, 2011

Batters on both sides are going after lots of those cutters just slightly out of the zone. Check out hitters' swing rate by location vs. Mo's cutter, compared to the league average:

Hitters' swing rate by location vs. Rivera's cutter, 2011League average swing rate by location vs. cutters, 2011 Rivera rarely throws a fastball to a lefty, but he uses the pitch about 18 percent of the time against righties. While his cutters sit mostly on the outside corner to same-handed batters, he ties them up inside with the fastball:

Frequency of Rivera's fastball location vs. righties, 2011

That, in turn, leads to lots of awkward swings on would-be balls:

Right-handed hitters' swing rate by location vs. Rivera's fastball, 2011League average swing rate by location for righty batters vs. righty fastballs, 2011Overall, Mo has thrown about 45 percent of his pitches within the strike zone this season. That may be well below the 49 percent average, but that's by design -- he's trying to locate just out of the zone, forcing batters to swing at pitches that they don't have much chance of hitting but may be called strikes if they don't pull the trigger. MC Hammer's 15 minutes of fame passed long ago, but the Hammer of God can still tell hitters, "can't touch this."

Mo troubles for Rivera

After giving up a home run to Bobby Abreu of the Angels, the greatest reliever of all time, the Yankees' Mariano Rivera, said to Kevin Kernan of the NY Post, 

“The pitch didn’t get there enough. It was middle in, not in enough. He put good wood on the ball. You have to make sure you get it there. It didn’t get there.”

"Not getting there" is also what happened in his previous appearance Sunday night when Mo gave up a double that went high off the Green Monster to Boston's Marco Scutaro.

But what does "not getting there" really mean? Mariano is referring to his cutter that for so many years broke so sharply that he sawed off bats like they were dry kingling. Kernan write that when Yankee manager Joe Girardi was asked how often the cutter does not cut, he answered,

“Very, very seldom. You don’t see it very often, and he happened to throw one tonight.”

Girardi is an honorable man, but the liklihood is that he is protecting his superstar by not adding, "But it's happening more frequently these days."

Let me show you what I mean.

Mariano's cutter in 2009

Batters hit .170 against Mo in 2009Look at the consistency in the pitches. The more he hit a spot, the more red appears. Mariano was cruel against lefties. He held them to a .174 avg. because they coudn't get around on the pitch. Righties couldn't reach the ball, they hit .165 against him.

Mariano's cutter in 2010

Batters hit .185 against Mo's cutter in 2010Look at the green and yellow start to grow. Those were the first signs of the cutter not cutting as much. It's by no means significant here but serves more as an indicator. As that ball drifted toward the middle, it was lefties that saw the first benefits. They hit hit .218 against him last year. Mo still owned righties however holding them to a .139 avg.

Mariano's cutter in the first half of 2011

Batters hit .214 against the cutter leading up to the breakLook how much of the plate Mariano took in the first half with the cutter. The red area now covers a good portion of the middle of the plate. Lefties were up to .224 against him as they put more balls into play with the good part of the bat. Righties were up to .204. Now I know .204 is nothing, but when you compare it to .139, it's something.

Mariano's cutter since the 2011 All-Star break

Batters are hitting the cutter at a .303 rate since the breakOverall, batters are hitting .263 in games in the second half of this season. His ERA is 3.48. As for the cutter, you can see it's "not getting there." Lefties are hitting .350 against it, righties .231. But there's more as Mark Simon of ESPN.com points out in his comprehensive look at Mariano,

"Rivera is not putting hitters away with two strikes as well as he usually does.....He's given up 16 hits in favorable two-strike counts (0-2, 1-2, 2-2) this season, nearly twice as many as he did in 2010 (9)." 

Does this mean that Rivera is done? By no means.

His ERA this season is 2.23 and his career ERA is 2.23. His WHIP is still a sparkling 0.992.

But it does mean is that like the continental drift, Mariano's cutter is clearly moving, slowly but surely into the territory of mere mortals. And that is not the way we are accustomed to describing Mariano Rivera.

The dulling of Mariano's cutter

It is becoming increasingly apparent that we are finally seeing the aging of Mariano Rivera. The great Yankee closer earned his 23rd save on Saturday, but it took a lot of work. While he struck out two, he brought the tying run to the plate (twice) by giving up two hits. Most significantly, he threw 28 pitches. This is the seventh time in 37 (18.9%) appearances he's thrown 20+ pitches in part, because batters are now able to work Mariano more effectively.

2009 Mariano vs. 2011 Mariano

As broadcasters repeat ad nauseum, Rivera is (primarily) a one pitch pitcher; he throws the cutter.

Here is the Mariano cutter in the first-half of 2009

Look at the consistent placement of Mo's 483 cuttersThrough July 14 of 2009, Mariano faced 119 batters, walked one and struck out 38. Batters hit .178, slugged .280, and had a .465 OPS. He had a 31.9% strikeout rate.

Here is the Mariano cutter in the first-half of 2011

This season, his 406 cutters are drifting more toward the center of the plate and upward, two dangerous places

In the first half of 2011, Mariano faced 106 batters, walked three and struck out 25. Batters hit .214, slugged .252, and had a .488 OPS. He had a 23.6% strikeout rate.

Beyond the slight drift upward of the pitch and the slight drift upward of the stats, there is a slight drift upward in the swing rate (49.5% to 53%), and a slight decrease in the miss rate (17.2% to 15.3%). Beyond that, there is an increase in the play rate 33.5% to 36.3%

2009 Mariano vs. 2011 Mariano against lefties

The difference is even greater versus lefties, take a look.

Here is the Mariano cutter in the first-half of 2009 against lefties

In 2009, lefties hit .167You can see that Mariano primarily worked inside, but he still worked enough on the outside to throw batters off.

Here is the Mariano cutter in the first-half of 2011 against lefties

In 2011, lefties are hitting.224The difference isn't vastly significant, but enough so that you can see why lefties are having more success this season. The pitches that Mariano used to throw on the outside are now being thrown more frequently inside and high.

Mariano will undoubtedly get the 20 saves he now needs to be the all-time saves leader, but he is going to have to work harder and his decreasing save percentage rate (98%, 96%, 87% to 85% this season), will most likely continue.