James Paxton is the Mariners best starting pitcher

The Mariners have problems. There, I said it. I am the first brave blogger to observe this fact, and I am rewarding myself with a nice, hot, cup of coffee from my Aeropress. Please hold on for a moment....

Mmmmmm delicious.

Coming into the season if you asked me for one segment of the Mariners that could be among the league's elite I would have said the starting rotation. Felix Hernandez, Hisashi Iwakuma, Taijuan Walker, Wade Miley, and Nate Karns were not a sure thing, pitchers almost never are, and a collection of pitchers even less so. But it did feel like if the starters hit something like their 80th percentile outcome the Mariners could have one of the strongest, deepest rotations in the American League.

"Oh yeah", someone like me would say, "and I guess if they need a few starts there's always James Paxton sitting in Tacoma."

The rotation has not been terrible. Mariner starters have an FIP of 4.26, good for sixth in the American League. But they haven't been the dominant, elite unit it felt like they could be. Karns and Walker flash big stuff and dominate at times, but struggle with nagging injuries, and inconsistent mechanics that lead to command issues and short starts. Hisashi Iwakuma appears to be in the full grip of age-related decline, and Wade Miley simply hasn't looked like he's belonged in a big league rotation the majority of the year.

The starters have particularly been struggling in June, albeit while running a likely unsustainable BABIP (.330), LOB% (65..0%), and HR/FB% (21.6%)  As the schedule toughened, and Felix Hernandez went on the Disabled List, Mariner starters have only been averaging five and a half innings per start, putting significant pressure on an injury depleted, scuffling bullpen.

Sometimes, there's a man:

(image courtesy of the treasure that is Manny Acta's Twitter account)

We continue to use this images like this, but again, here is Fangraphs' top 10 fastest fastballs (min. 20 IP):

There are seven relievers on that list, and three starters. There is one left-hander. There is one left-handed starter. That is James flippin' Paxton.

Through four starts Paxton has shown the ability not only to throw the hardest left-handed fastball of any starter in baseball, but whichever heathen Canadian god he made sacrifice to between Cheney Stadium and his flight to Petco Park has allowed him to throw more strikes than ever before. His Zone% (number of pitches in the strike zone) is 52.9%, compared to his career rate of 46.9%. This has Paxton, predictably, at a career low BB% of 6.0.

In addition to his improved command and sudden acquisition of Randy Johnson's fastball, Paxton has begun throwing a tight, darting, 90 MPH cutter twenty-three percent of the time. Back on June 1, when Paxton gave up six runs in a disastrous first inning in San Diego, he did not throw that pitch once. Since that one inning, he has been utterly dominant:

21 IP, 23 H, 8 R, 28 K, 6 BB

It feels incredibly, terrifyingly fragile. Beyond even the obvious small sample size concerns, Paxton has never, never shown velocity like this, including his time this year in Tacoma. He has never shown the ability to throw strikes like this. Add on that, through injury and inconsistency it has taken from his major league debut, way back on September 7th, 2013, until now for Paxton to assemble a career sample size approaching a full season in the big leagues and I think we're just waiting for it to go wrong.

I am not a scout, and I am not a pitching mechanics expert. I know only what I see and the numbers tell me, and if there's anything about James Paxton's four starts in a Mariner uniform that screams "Regression Candidate" it is not his current success, but rather his .403 BABIP against and 17.6% HR/FB. His results could actually improve, and do so substantially.

Nothing in baseball is static, and among the hundreds of human beings selling their ability to play this game as a sort of stock James Paxton's "feels" like one of the most volatile. But, for right now, there is no pitcher on this Mariner staff I want on the mound more than him. He is fit, healthy, happy, and commanding some of the very best stuff in all of baseball.

James Paxton, as I write this, is the Mariners best starting pitcher.

gobiz