Traditionally, the Arizona Fall League is reserved for the top Double-A and Triple-A prospects in each organization.  We’ve previously seen with players like David Wright and Mike Piazza having played in the Arizona Fall League.  We see it again this season with top prospects like Kyle Tucker (Astros), Ronald Acuna (Braves), and Francisco Mejia (Indians).

The list of players in the Arizona Fall League this year also includes 29 year old Mickey Jannis.

Typically speaking, when a prospect passes a certain age, they are no longer considered a prospect.  Depending on which standard you apply, that age is a moving date, but everyone will agree that 29 years old is too old to be considered a prospect.

Jannis is different than your typical prospect because he is a knuckleball pitcher, and for a number of reasons knuckleball pitchers have a tendency to develop later in their careers than most prospects.

There are few pitching coaches out there who are actually adept at teaching the pitch, and it is a difficult pitch to throw.  However, the main reason is probably due to it being seen as gimmick which pitchers do not seek to learn until their careers are almost at a premature end.  Jim Bouton described this process best in Ball Four:

After a couple of year in the minors, however, I started to get bigger and stronger and started to overpower people with my fastball.  So I phased the knuckleball out.

I never really used it again until 1967.  My arm was very sore and I was getting my head beat in.  [Ralph Houk] put me into a game against Baltimore and I didn’t have a thing except pain.  I got two out and then with my arm still hurting like hell, I threw four knuckeballs to Frank Robinson and struck him out.  The next day I get sent to Syracuse.  Even so, it wasn’t until the last part of the next season that I began throwing it again.  The idea that you’ve lost your regular stuff is very slow in coming.

That experience is typical to most knuckleballers.  In R.A. Dickey‘s own book, Wherever I Wind Up, he stated his process of learning the knuckleball began when the Rangers front office suggested it was his best chance of being able to have a Major League career.  That is an experience shared by Jannis:

It’s just a decision I made after I got released by the Rays after my second year in pro ball.  I went into independent baseball and just made the transition. It’s been a long process. I’m still learning to throw it, learning to throw it for strikes. It’s just every day learning something new with the pitch.

(William Boor, MLB.com)

In many ways, Jannis is still learning how to control the pitch, and as a result, he has had middling results.  He would go from a 3.55 ERA and 1.354 WHIP in 2015 to a 5.69 ERA and 1.564 WHIP in 2016.  This made his age 29 season an important one to improve his status as a prospect.  Based upon recent knuckleball pitchers age 29 season, there wasn’t much reason for hope:

• Tim Wakefield (1996) 14-13, 5.14 ERA, 1.550 WHIP
• Dickey (2004) 6-7, 5.61 ERA, 1.620 WHIP

Albeit in Double-A, Jannis had a much better age 29 season going 8-7 with a 3.60 ERA and a 1.251 WHIP.  During the season, he’s come closer to taming the knuckleball leading to better success, a rejuvenation of his status as a prospect, and his assignment to the Arizona Fall League.

Jannis has taken full advantage of the opportunity by pitching great.  In his six starts, he was 1-3 with a 2.33 ERA and a 1.037 WHIP.  Overall, he’s showing he control his knuckeball, and he can get baseball’s top prospects out.  If he continues learning how to harness his knuckleball, he may very well get the chance to prove he can use it to get Major League batters out.

EDITOR’S NOTE: This was first published on MMO