Jansen nails down top reliever ranking Right Now

MLB Network's "Top 10 Right Now" series ranks Major League Baseball's top players at each position headed into 2018, with two episodes airing each Saturday, beginning on Jan. 13 and ending tonight. MLB.com's Mike Petriello participated in the show, and we're sharing his list along with the reasoning behind it. Rankings were compiled with a combination of subjective and analytical data, and no, wins and saves never matter.
Position overview: Relievers are more important than ever before, but our list also reflects the changing nature of the position. Saves don't matter -- not that they ever did -- and pitchers who can go more than one inning have become increasingly important. That's why our Top 10 reflects a combination of both.
Before we get to my list, here is The Shredder's list -- the official ranking of Top 10 Right Now -- for comparison. This list was created by the MLB Network research team and is to be considered entirely separate from my list.
1. Kenley Jansen, Dodgers

2. Andrew Miller, Indians
   
3. Craig Kimbrel, Red Sox
   
4. Chad Green, Yankees
   
5. Archie Bradley, D-backs
   
6. Zach Britton, Orioles
   
7. Corey Knebel, Brewers
   
8. Aroldis Chapman, Yankees
   
9. Brad Hand, Padres
   
10. Raisel Iglesias, Reds

Petriello's list
1. Kenley Jansen

2. Craig Kimbrel
   There's no doubt who the Big Two at the top of this list are. You can argue for either order here, probably, but for us it's pretty clearly Jansen -- if only because it's difficult to understand how any reliever could possibly be more dominant than he was last year. Remember, he started off the 2017 season by striking out 51 hitters before his first walk, ending up with a ridiculous 109/7 K/BB ratio. He was first, by a lot, in the most advanced Statcast™ quality-of-contact metric. He basically throws one pitch, except when he doesn't; he may just end up being the best reliever we've ever seen.
   None of which takes anything away from Kimbrel, of course. After a good but strangely shaky first year in Boston, Kimbrel upped his strikeout rate from 38 percent to 50 percent, thanks in part to high heat, while also cutting his walk rate from 14 percent to six percent. Oddly enough, Kimbrel allowed a 91.1 mph average exit velocity, the highest of any reliever, so he wasn't preventing hard contact. But a 50 percent strikeout rate tells you, of course, contact against Kimbrel was hard to come by in the first place.
   3. Andrew Miller
   Other than a two-week trip to the disabled list for a knee injury, Miller did what he always does -- dominate -- though it says a lot about him that he was simultaneously "less great than in previous years" and "still really, really great." Though his ERA remained steady, his strikeout rate dropped from 45 percent to 39 percent, while his walk rate nearly tripled, to nine percent. He's the complete opposite of Kimbrel in one way, because he allowed the weakest average exit velocity among relievers, at 81.3 mph. We're now up to six straight years of relief greatness from Miller.

4. Felipe Vázquez, Pirates
The 2016 trade that sent Mark Melancon to Washington was unpopular in Pittsburgh at the time, but now it looks like an absolute steal, as Rivero has blossomed into one of the best relievers in the game. Mostly, that's because of his elite fastball; among lefties over the last five years, only Chapman has thrown more triple-digit pitches than Rivero's 112. But even looking at his non-fastball pitches, mainly a change and slider, he allowed a .103 average and .159 wOBA against.
Rivero was baseball's best pitcher against lefty batters, too, allowing a .082/.161/.094 line. He's one of baseball's best relievers, period.

5. Roberto Osuna, Blue Jays
It seems like Osuna gets lost in the shuffle of elite relievers, perhaps because he's not even 23 until next month. It's pretty difficult, however, to look past the 83/9 K/BB he just put up, or that he's got 240 strikeouts in 207 2/3 innings. By that same all-encompassing Statcast™ metric we mentioned for Jansen, Osuna was in the Top 10, basically tied with Miller. Not only that, he's been improving each year; his strikeout percentage has gone from 28 percent to 29 to 33; his walk rate has dropped from six to five to four. He may not get the same attention as the others, but he is elite.
6. Aroldis Chapman
That Chapman had a "down season" tells you a lot about how good his seasons before 2017 were; Chapman still struck out 69 in 50 1/3 innings and averaged 100.2 mph on his fastball. Mostly, this is about a bad August slump, during which he threw eight innings, allowed eight runs, and struck out just eight. After that, he came out in September and struck out 17 across 12 scoreless innings, walking two. He'll be just fine. He's still baseball's preeminent power arm.

7. Sean Doolittle, Nationals
The risk with Doolittle is always health, as he missed several weeks of 2017 with a shoulder strain, the latest in a litany of injuries. Even still, he got into 53 games between Oakland and Washington, and he did so with his usual fantastic performances. A 62/10 K/BB is nice enough, but he also finished third in our Statcast™ contact quality measurement, thanks to Top 10 exit velocity suppression. He's been elite ever since he debuted in 2012, really. He just needs to stay healthy enough to show it.

8. Chris Devenski, Astros

9. Chad Green
   We're lumping these two together because they're similar multi-inning relievers who have proven to be invaluable parts of American League playoff teams. (They were even each acquired as little-known prospects from AL Central clubs.)
   Devenski got there first, arriving on the scene in 2016 to toss 108 1/3 fantastic innings of 2.16 ERA ball. He followed that up with a 2017 that proved it wasn't a fluke; his whiff rate jumped from 26 percent to 32 percent, while his average against dropped from .205 to .174. While he stumbled somewhat in the second half, he still killed lefties, posting a .110/.178/.236 (.184 wOBA) line and throwing at least an inning in 50 of his 62 games.
   Green was more of a breakout star, starting the year in the Minors and not sticking in the bullpen until May. When he did, his performance was stunning -- in 69 innings, he had 103 strikeouts and just 17 walks. Like Devenski, he became a multi-inning weapon, averaging five outs per appearance. All of this was mostly thanks to his fastball, which had a best-in-baseball 39.8 percent whiff rate.
   10. Cody Allen, Indians
   Due to Miller, it's easy to forget just how good Allen has been in Cleveland's bullpen for years. He has four straight seasons with a strikeout rate of 33 percent or higher; he has been above-average in each of his five full seasons. It says something about modern baseball, perhaps, that the guy racking up the saves is very clearly seen as the second banana in his own bullpen.
   Just missed (in no order):David Robertson, Yankees; Tommy Kahnle, Yankees; Dellin Betances, Yankees; Ken Giles, Astros; Archie Bradley; Corey Knebel; Raisel Iglesias; Pat Neshek, Phillies; Wade Davis, Rockies; Brandon Morrow, Cubs
   Look at all those Yankees. No wonder we were wondering if they might possibly have the best bullpen of all time. Really, there's so much talent here that it's easy to prefer any of these names over the back half of our Top 10; it comes down to preference. Knebel in particular was a difficult omission due to his standout 2017, but nearly five walks per nine pushed him just ever so slightly off.