Billy Stonick examines whether starting pitchers (SP) Patrick Corbin, Carlos Rodon, and Martin Perez are fantasy baseball contributors or just getting lucky.

As the saying goes, you can’t win your league during the draft. The waiver wire moves owners make during the season are the ones that will determine who wins. The art to winning at fantasy baseball is being able to determine who should be added to a roster and should be bypassed. In order to do that, an owner needs to be able to tell if someone is for real or not.

This column will focus on some pitchers who have recently thrown their hats into the ring for consideration. Below are some pitchers who performed well in Week 19, as we look towards the waiver wire for Week 20 and beyond.

These pitchers are available in many leagues, and we’ll dig a little deeper to determine whether you should be picking these guys up or leaving them be.

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Tommy John and the Wild One

Patrick Corbin, Arizona Diamondbacks

2016 Stats: 155.2 IP, 5.15 ERA, 1.56 WHIP, 131 K (7.57 K/9), 66 BB (3.82 BB/9)

August 12, 2017 vs. Chicago Cubs: 6.2 IP, 0.00 ERA, 0.90 WHIP, 8 K (10.80 K/9), 1 BB (1.35 BB/9)

At the tender age of 23-years-old, Patrick Corbin looked like a kid embarking on a solid future. He went 14-8 with a 3.41 ERA that revolved around an unimpressive strikeout rate, a basement-dwelling walk rate, and a knack for keeping hitters off-balance. He drew slightly more ground balls than the average starter, but his real talent was simply limiting mistakes. He was nothing special from a fantasy perspective, but anyone posting a sub-3.50 ERA with a sub-3.50 FIP to back it up had a smooth path ahead of him. Unfortunately, Tommy John surgery would steal 2014 from him, but when he came back late in 2015, he looked like he was ready to roll as he was able to log a 3.60 ERA over 85 innings to close out the year. Instead, a reckless version of Corbin showed up in 2016. His ERA skyrocketed to 5.15 with a frightening 1.56 WHIP to go along with it. His walk rate shot up well above league average, and his strikeout rate didn’t offset it. Overall, it was like a whole new pitcher had arrived, and he was wild. 2017 started with a mixed bag as he logged a 2.29 ERA in April followed by a perfect 9.00 ERA over 26 innings in May. He’s since settled down somewhat, but his season numbers are still recovering from that ugly May.

On August 12, Corbin took the hill against the Cubs. Though his season stats are scary, this outing was nothing of the sort. Corbin blazed through 6 and 2/3 shutout innings on the way to his first win of August. He struck out eight and only walked one, and he gave up a measly five hits over the course of the outing. He didn’t just look like the Corbin of old; he looked like a whole new Corbin. And this Corbin brought the Ks.

While Corbin’s stats for the 2017 season look ugly at first glance, his recent ones are much nicer to peruse. For example, Corbin’s 2017 ERA is 4.52. His ERA over his last 10 appearances is 3.61. His strikeout rate for the season is a career-best-but-just-slightly-above-average 8.84/9. His strikeout rate for the last 30 days is 10.06, the 21st best rate in the league. His K-BB% of 18.3% is top-30 in the league. This pattern has led to other good things, such as the fact that he’s only allowed more than three earned runs in one of his last 10 starts.

Verdict

Most pitchers take about 18 to 24 months to get back to their full level of performance after Tommy John surgery, but this isn’t Patrick Corbin getting back. This is a new version of Corbin that regained his old pinpoint control and buries his pitches better than he used to. This is a version of Corbin that doesn’t just limit hitters, he eliminates them. He has posted a K-BB% of 16.3% or higher in each of the last three months. His xFIP during that period has never gone above 3.52. This version of Corbin is the real deal, and if he can keep his strikeouts high and walks low, he’s going to be an excellent pitcher.

Carlos Rodon, Chicago White Sox

2016 Stats: 165.0 IP, 4.04 ERA, 1.39 WHIP, 168 K (9.16 K/9), 54 BB (2.95 BB/9)

August 10, 2017 vs. Houston Astros: 8.0 IP, 2.25 ERA, 1.13 WHIP, 4 K (4.50 K/9), 0 BB (0.00 BB/9)

The hype around Carlos Rodon has been there for years. Drafted in June of 2014, Rodon would be in Triple-A before the end of the season, having pitched just 12 and 2/3 innings at lower levels. He threw 139 and 1/3 innings in the majors the very next year. Outside of rehab starts, he’s never left. The book on him has been pretty well established over the last three seasons: strikeout stuff with control problems. It’s not a rare problem amongst young pitchers, and Rodon has been the king of the mountain at the major league level. He posted the worst walk rate of any major league pitcher that threw 120+ innings in 2015, 4.59/9. However, even though the stereotype stuck, he sunk that walk rate dramatically in 2016, all the way down to 2.95. That was below average! Thinking he had permanently changed, many drafted him early in 2017. Injuries kept him sidelined until late June, and when he returned, he was back to his wild ways. He actually had a 6/2 BB/K ratio in his first outing of the year. Many abandoned ship after he posted 18 walks in his first five starts, and his 6.29 ERA at the time didn’t help matters.

On August 10, Rodon faced off against the first-place Astros. The Astros aren’t just good; they’re great. Especially offensively. That didn’t faze Rodon though, as he tossed eight brilliant innings while only surrendering two runs. He was only able to strike out four along the way, but most importantly, he didn’t walk anyone. For Rodon, that figure is critical.

Rodon has walked zero hitters in a start on five separate occasions in his career. In all five starts, he threw a quality start. In fact, he’s never surrendered more than two runs in such a start. He’s also only had back-to-back zero-walk starts once in his career, on August 4, 2017 at Boston and August 10, 2017 against Houston. This could be the start of something big for Rodon.

Verdict

Carlos Rodon is still only 24 years old, and he’s got very good stuff. The key for him is to keep from issuing walks. If he can limit his walks, he’s the real deal. If he falls back into his old habits of filling the bases with free runners, he’s in for a world of hurt.

Now, even when Rodon does issue a free pass, his success rate is pretty high, but it's a fine line. To review, with no walks, Rodon has allowed no more than two runs in a single outing. With one walk, he’s allowed more than three runs in a single outing four times in fourteen possible instances. That means that if he can walk less than two batters in a game, he’ll keep the opposing team from scoring four or more in 79% of games. That’s giving his team a pretty good chance to win. However, as the walks go up, that percentage goes down. Just one additional walk per game drops it nearly 10%. Rodon’s got good stuff, but he doesn’t have the level of stuff necessary to escape unharmed from 3+ walks per outing. Owners should prepare to cut ties with him if he starts to get wild once again.

Martin Perez, Texas Rangers

2016 Stats: 198.2 IP, 4.39 ERA, 1.41 WHIP, 103 K (4.67 K/9), 76 BB (3.44 BB/9)

August 9, 2017 at New York Mets: 8.0 IP, 1.13 ERA, 0.38 WHIP, 5 K (5.63 K/9), 0 BB (0.00 BB/9)

At just 22 years old, Martin Perez landed a regular spot in the Rangers starting rotation in 2013. He’d had an unimpressive debut the season before when he posted a 5.45 ERA in 38 innings, but Texas has been desperate for starting pitching for decades, so it’s not a high bar to get over to qualify for their starting five. Besides a shiny 2011 campaign at Double-A and a quick start to the 2013 season at Triple-A, Perez had never posted an ERA under 4.00 at any minor league level. However, he cobbled together 124 solid innings in the bigs in 2013 and finished with a 3.62 ERA. The statheads said it was a fluke, and they were right. Perez wouldn’t pitch well to start 2014 and the lefty would eventually end up having Tommy John surgery, costing him the rest of 2014 and most of 2015. He returned in full force in 2016, but he proved to still not be a good pitcher, posting a 4.39 ERA, 1.41 WHIP, and the worst strikeout rate amongst qualified starters in the majors, 4.67 K/9.

On August 9, Perez faced the Mets for the first time in his career. The Mets of 2017 are not the recent World Series contender. They’re not even a good team, and Perez treated them like the doormats they are. He tossed eight strong innings, allowing just one earned run while striking out five and walking no one. It was an excellent outing for Perez, and with the Rangers starting pitching in perpetual shambles, outings like this one will probably help him retain his position instead of getting bought out by the club at the end of this season. It will also lure in some fantasy owners. Don’t be one of those.

Perez’s start against the Mets does come right around the time that Tommy John recipients start to get their feel back, but this start is a prime example of what a small sample size can do to an owner. Some may think that this is Perez turning a corner, but it’s important to note that this start was the epitome of a bad pitcher getting lucky. He had a below-average strikeout rate, he stranded 100% of runners that reached base against him, batters hit just .100 on balls in play against him, and he even drew the least amount of ground balls that he had drawn in a single outing since the start of June. Hands-down, this was Perez’s best outing of the season, and it was entirely built on the back of blind luck.

Verdict

Not only is Martin Perez not the real deal, it’s surprising his job isn’t constantly under threat. Perez doesn’t just struggle at striking hitters out, he’s one of the very worst at it in the entire league. Prior to August 9, the last time he surrendered less than three runs in an outing was June 10. He’s surrendered home runs in six straight starts, and he’s given up the 13th most home runs in the league in the last 30 days. Perez is the perfect example of someone who will draw fantasy owners in by having one good start, but he should be avoided at all costs.

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