Is it Legit? Blake Snell's 2018 Breakout

We continue with our next edition of "Is It Legit?" to discuss another surprising breakout performer from the 2018 MLB season in order to assess his value heading into 2019.

With so many players seemingly becoming fantasy baseball darlings overnight, it can be challenging to sift through the multiple hype trains and determine which players are actually expected to produce similar, or even better, numbers the following year.

Perhaps no pitcher made more improvements across the board last season than Rays starter Blake Snell, who went from posting a 5-7 record with a 4.04 ERA and 1.33 WHIP in 2017 to an elite 21-5, 1.89 ERA, 0.97 WHIP season last year that culminated in a Cy Young award for the 26-year-old left-hander. Snell will no doubt be one of the most highly sought after starters in fantasy next year, but are his numbers from last season legitimate or is he a case of smoke and mirrors?

Can Snell Repeat in 2019?

Taking a look at Snell's numbers from last season is a lot of fun. The first, perhaps most notable, thing that might scare fantasy owners away is his 2.94 FIP - indicating that his 1.89 ERA is probably unsustainable going forward. Duh. I don't think anyone would, or should, expect Snell to post back-to-back sub-2.00 ERA seasons. Still, a 2.94 ERA is something you'll take day in and day out, so no worries there. Plus, Snell's first-half ERA of 2.27 came down to a staggeringly low 1.17 in the second half.

In fact, let's take a look at Snell's second-half numbers, across 61.2 innings pitched:

1.17 ERA
0.79 WHIP
87 Strikeouts (12.70 K/9)
17 Walks (2.48 BB/9)
.153/.217/.242 Opponents slash

No other way to look at it, Snell was flat-out dominant in the second half of the season. But again, can this type of production sustain into 2019?

Snell's breakout was fueled by a massive improvement in his strikeout rate and his walk rate. He went from an 8.28 K/9 to 11.1, and dropped his walk rate from 4.11 BB/9 to 3.19. Al Melchior of Fangraphs took a look at walk-rate breakouts, and came to the conclusion that players who drop their walk rate suddenly have a good chance of repeating it the following year, although it is by no means a guarantee.

Snell certainly made what appear to be sustainable improvements to his command, improving his first pitch strike rate by over 3% and his overall zone rate by 1.5%. Plus, an increase in opponents chasing pitches out of the zone helped as well.

Still, seeing a player's walk rate plummet like Snell's is a bit of a cause for concern. Even with the improvement to his zone rate, he still throws the ball out of the strike zone over 60% of the time. If his walk totals creep back up next season, his value will come down.

On the other side, Snell's strikeout stuff does look somewhat sustainable. Obviously, his 0-swing (or chase) rate improving was a big part of his success, as was his first pitch strike rate. He also saw his swinging-strike rate improve from 10.8% to 15.1%, a massive change that helped lead to a 10% increase in strikeouts.

Part of that change was a big increase in his curveball usage, which spiked from 10.3% thrown in 2017 to 20.2% in 2018. That curve was one of the best pitches in all of baseball, earning a 24.5% swinging strike rate, a 45.4% chase rate and a 13.7 pVAL. Basically, Snell realized that using his best pitch 10% more often is a good thing. Who knew?

Of course, hitters may adjust to Snell's curveball in time, but one can expect that he will rely on that pitch a lot in 2019, which should help keep his strikeout numbers up.

STEAMER projects Snell to post a 3.23 ERA, a 1.19 WHIP, a 11.01 K/9 and a 3.59 BB/9. That points to some regression for the Cy Young winner, which is to be expected. That also points to a top-ten starting pitcher in all fantasy formats, meaning he should still be drafted quite highly - particularly in leagues that value K/9.

If fantasy owners want to reach for Snell as the No. 1 or 2 pitcher off the board, let them. But as the No. 7-9 arm, I'd be happy to snag Snell and get that strikeout potential for 2019.