When Kenley Jansen converted to reliever from catcher in the middle of the 2009 season, no one knew how he would transition.
Two years later, it's abundantly clear that not only was it the right choice, he has a chance to be a really special pitcher in the back end of a bullpen.
Jansen had a great debut season in 2010, posting a minuscule 0.67 ERA and a 1.00 WHIP. He also posted an ungodly 582 ERA+ and 13.7 K/9 rate. While his ERA and WHIP aren't as good as his 27-inning debut season, he's been arguably better in 2011 and nearly unhittable since returning from the minors and disabled list in the middle of June.
Since June 18, his numbers have been video game-like:
24 2/3 IP, 6 H, 1 R, 10 BB, 42 K (15.2 K/9)
0.36 ERA, 0.65 WHIP, .077 BAA
Like I said, video game-like. The most impressive number might be the one run allowed, which he gave up on Sept. 1.
Jansen's K/9 rate is 15.18, which, if he keeps up his current pace, would be the second-highest of any reliever in MLB history behind Carlos Marmol's insane 15.99 K/9 rate in 2010.
While Javy Guerra has gotten a lot of praise for the job he's done as the Dodgers' closer, Jansen has been the best reliever in the National League -- if not the Majors -- in the last nearly two months.
So what's made him so dominant? It has to be the addition of his cut fastball.
Prior to the season, the big question surrounding Jansen was how was he going to compliment his mid-90s fastball? His slider has potential, but is inconsistent. His curveball is a last-resort-type pitch.
So, he decided to throw a variation of a fastball.
Former Dodger and Yankee Dioner Navarro said Jansen's cutter reminds him of Mariano Rivera's cutter.
When I watched Jansen pitch on Saturday night against the Giants, I couldn't help but think the same.
Jansen gave up one hit before striking out two of the three remaining batters to get out of "trouble." He got Aubrey Huff on three consecutive cutters -- all of which were in the strike zone, but Huff had zero chance of hitting them.
Rivera has made a career on one pitch, because he threw is with pinpoint accuracy, velocity and incredible movement. Jansen's cutter isn't there yet -- and might not ever be -- but it has the potential to be on the level.
According to Texas Leaguers, in 2011, Jansen has thrown his cutter 71.7 percent of the time. In September, he's thrown it 88.6 percent of the time. He's thrown it harder now than he did earlier in the season, too.
Cutter velocity 2011: 93 MPH
Cutter velocity in September: 94.3 MPH
He's pretty much abandoned his other pitches. Now, he might have to develop an off-speed breaking pitch in the future, but for now, he's riding his cutter, ala Rivera.
It's worked for Mariano, why not Kenley?
To stick with the Jansen/bullpen theme....
Eric Stephen of True Blue L.A. beat me to it, but it also broke down Jansen's dominance since returning from the disabled list.
Chad Moriyama of the aptly named, ChadMoriyama.com, has a great breakdown of the Dodgers' bullpen and how the "cheap" guys are actually the best pitchers (also published on TBLA).