Corbin's slider-heavy approach about to pay off

The top starting pitcher in the 2019 free-agent class is also the perfect representative for the evolving philosophy on the mound in the modern game.
The pitcher: Patrick Corbin, the 29-year-old D-backs left-hander who had the strongest season of any free-agent-to-be hurler, posted a 3.15 ERA over 33 starts, striking out 246 batters in 200 innings and amassing 6.3 Wins Above Replacement, per FanGraphs. The philosophy: Throw your best pitch more often, even if it's not your fastball, and even at the fastball's expense.
Corbin is slider-dominant -- one of the heaviest slider users among starting pitchers. He threw sliders 40.9 percent of the time in 2018, his most-used pitch by more than 10 percent over his sinker (29.5 percent). Combining that with his curveball, Corbin threw breaking pitches 50.3 percent of the time this season. Only Clayton Kershaw threw more. They were the only regular starters who threw breaking balls on more than half of their pitches.
Highest breaking ball* usage rate among starting pitchers in 2018
Minimum 1,000 total pitches thrown (166 starting pitchers)

1. Kershaw: 56.6 percent
   2. Corbin: 50.3 percent
   
2. Garrett Richards: 49.6 percent
   
3. Jordan Zimmermann: 49.0 percent
   
4. Jon Gray: 48.7 percent
   Breaking: Curveballs, sliders, knuckleballs
   Not too long ago, Corbin's style of pitching would have been rarely seen. Now, it's become increasingly prevalent in today's MLB. And it's going to earn Corbin a big free-agent contract.
   The results speak for themselves. On the 356 plate appearances decided on Corbin's slider, opposing batters hit just .145 and slugged just .243. Corbin racked up 195 strikeouts on sliders alone, meaning 54.8 percent of those 356 plate appearances resulted in a K. Batters missed on 53.7 percent of their total swings at Corbin's slider -- 387 of 721 -- the highest slider whiff rate generated by any starting pitcher.
   It was, simply, a dominant pitch, and Corbin made sure to use it as such. Consider this: Corbin's 196 strikeouts on sliders were 71 more than any other pitcher. His 387 total swings-and-misses on sliders were 176 more than any other pitcher. That's an incredible gap. No Major League leader in strikeouts or swings-and-misses on any other pitch type had as large a margin over the next-closest pitcher.

Most strikeouts on sliders in 2018
1. Corbin: 195

2. Jakob Junis: 124
   
3. Luis Severino: 119
   4 (tie). Chris Sale: 117
   4 (tie). Dylan Bundy: 117
   Most swings-and-misses on sliders in 2018
   1. Corbin: 387
   
4. Chris Archer: 211
   
5. Severino: 200
   
6. Gray: 189
   
7. Bundy: 187
   There's a strong chance Corbin ends up with the largest deal of any free-agent starter. If Kershaw doesn't opt out of his contract with the Dodgers, Corbin's main competition would be Dallas Keuchel, J.A. Happ and Charlie Morton, who are all older, or maybe even someone like Nathan Eovaldi, who's the same age, but more of a question mark, having just pitched his first season back from Tommy John surgery.
   His breaking-ball-first style makes him an outlier even when compared to other recent marquee free-agent starting pitchers. Out of all the free agent classes this decade, only once has the largest contract gone to a starter who didn't throw primarily fastballs. That was two years ago, when Rich Hill -- another face of the secondary-stuff-first movement, whose curveball-heavy approach sparked his remarkable Major League comeback -- was the top starting pitcher signee, getting a three-year, $48 million deal from the Dodgers.
   Here are each of the top free-agent starting pitcher signings by year since 2010, how often they threw fastballs (four-seam, two-seam, sinker or cutter) in the season leading up to their free agency, and their most-used individual pitch:
   Top MLB free-agent starting pitcher signing by year, 2010-17
   2017: Yu Darvish (6 years, $126 million) -- 66.5 percent fastballs (most-used: four-seamer)
   2016: Hill (3 years, $48 million) -- 46.9 percent fastballs (most-used: curveball)
   2015: David Price (7 years, $217 million) -- 68.6 percent fastballs (most-used: four-seamer)
   2014: Max Scherzer (7 years, $210 million) -- 55.0 percent fastballs (most-used: four-seamer)
   2013: Matt Garza (4 years, $50 million) -- 63.5 percent fastballs (most-used: four-seamer)
   2012: Zack Greinke (6 years, $147 million) -- 64.3 percent fastballs (most-used: four-seamer)
   2011: C.J. Wilson (5 years, $77.5 million) -- 67.1 percent fastballs (most-used: sinker)
   2010: Cliff Lee (5 years, $120 million) -- 83.3 percent fastballs (most-used: two-seamer)
   But Corbin is on a different level than even Hill. Hill was more of a best-option-available signing, a 35-year-old veteran with a long injury history who embraced a forward-thinking approach to find new success in the big leagues. Corbin is a frontline starter in his prime whose best pitch is not his fastball, and that pitch is about to command a major contract.
   Interestingly, some of the teams he's been linked to leading up to Hot Stove season are no strangers to secondary-pitch-heavy starters. The Yankees -- who are expected to pursue Corbin and who look like an ideal fit for the left-hander -- already have Masahiro Tanaka, who throws fewer fastballs than any other starter in the Majors, at the top end of their rotation. The Braves, who also could look to sign Corbin, got a breakout year from Mike Foltynewicz in 2018 after Folty spiked the usage of his own wipeout slider, with a corresponding dip in fastball usage, even though he has one of the highest-velocity fastballs among starting pitchers.
   So while Corbin might be one of the first big-ticket, big-breaking-ball free-agent starting pitchers, he almost certainly won't be the last, especially if he and his slider pay off big for the team that signs him.