Is Jake Arrieta's 2014 formula for success a sustainable one?

The Chicago Cubs figure to be quite a bit better than seasons past in the upcoming 2015 campaign. There are a number of things to which we can attribute the newly found optimism on the North Side. Whether it's the wave of prospects, the new coaching staff, or the addition of Jon Lester, the buzz around Wrigley Field these days is completely justified. However, one of the key aspects these hopes hinge on is a player that is not new to the club.

Jake Arrieta had an absolutely fantastic 2014 for the Cubs. It was his first full year with the organization, having been acquired in 2013, along with Pedro Strop, in exchange for Scott Feldman in a deal with the Baltimore Orioles. His arrival in Chicago didn't come without risk, as he spent several years toiling in the Baltimore system, battling some serious control issues. He was always looked at as a high upside quantity, if he could ever harness that aspect of his game.

He did that in 2014, turning in 25 starts for the Cubs after an injury put the start of his season on hold. He pitched to a 2.56 ERA, a fabulous 2.26 FIP, and struck out 9.59 hitters per nine innings, the highest total of his sporadic Major League career. His ground ball rate also came in at a career high, which undoubtedly helped him on a Cubs team that was improved defensively in 2014, with a rate of just a touch over 49 percent for the year.

The reason for his improved performance wasn't extremely difficult to discern. He increased his slider usage (which some have quantified as a cutter), to the point where he just about doubled it, going from throwing it about 15 percent of the time to up over 29 percent in 2014. He induced more swings and misses with his curve as well, increasing that figure by about seven percent. That represented the most significant uptick in whiffs, as everything else remained relatively constant.

Arrieta also changed the way in which he attacked hitters. The following chart represents how Arrieta approached left-handed hitters in 2011, when he made 22 starts for the O's, his highest total before 2014:

Over the course of three years, and with a little Chris Bosio magic in Chicago, this is how Arrieta attacked lefties in 2014:

Simple observation gives a pretty strong indication of what changed for Arrieta. Rather than go outside, while leaving pitches up, Arrieta went at left-handed hitters low.That's an easy recipe for success, especially when you have the type of arsenal at your disposal that Arrieta possesses. It's the same recipe for success that he follows against righties, which has remained constant for much of his career. Both his 2011 and 2014 zone profiles look quite a bit like this:

It's a matter of harnessing command of his pitches, at least for the most part. Continuing to use 2011 and 2014 as the sample, as they are closest in terms of the number of starts, the increase in control is evident, and a large portion of the credit there is due to pitching coach Chris Bosio, who has done wonders with Arrieta. With the exception of the slider and curve, which have both increased dramatically in terms of usage, everything else has come down in percentage of balls thrown, as opposed to strikes. As a result, Arrieta walked just 2.36 hitters per nine last season, which represents a career best for him at any level.

It's a simple formula, or at least it appears that way, that allowed Arrieta to bounce back the way he did last season. The question for Arrieta now becomes how he spins that success into something sustainable. Given the way in which he's done it, in improving his command and pitch location, in addition to changing usage of his pitches, it's a formula that can dictate success that is absolutely sustainable. While a regression of some sort may be expected, especially due to a quite low .274 opposing BABIP last season, he should continue to represent stability as a no. 2 starter for the Cubs as they move into their years of contention.

Statistics via FanGraphs.
Usage and outcome numbers via Brooks Baseball.

Randy Holt is a staff writer for Beyond the Box Score. You can follow him on Twitter @RandallPnkFloyd.