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Swinging Strike Rate Risks

About this time last year, I was pretty enthusiastic about projecting and drafting Luke Weaver. The 2014 first-round pick by the Cardinals was coming off of a relatively strong half-season in majors, preceded by an excellent campaign at Triple-A Memphis. He had a 3.88 ERA, but also had 72 strikeouts in 60.1 innings. I grabbed him (exceedingly early) in an annual Scoresheet Mock Draft that I've been doing for six or seven years (and for what it's worth, the pick was panned by the room - each pick frequently draws a lot of intelligent comments from the room of high-level players). Much of the industry and my competition in the NFBC felt the same way. His final NFBC ADP was 109.97, with a range between 55 and 185 overall. I participated in a 15-team Draft Champions League comprised of industry members in January where he went at the 6/7 turn, and I was disappointed that I didn't get my shot towards the back end of the seventh round.

But my outlook on Weaver changed after reading Alex Chamberlain's "Finding Reasons to Doubt Luke Weaver" article on Fangraphs late in January. I met Alex at First Pitch Arizona in November of 2017 and am a big fan of his work. The gist of the article - as always, you should read the entire piece rather than rely upon my summary of it - was that Weaver's 2017 28.6% strikeout rate was unsupported by the quality of his stuff, and the underlying stats. In particular, Alex was worried about Weaver's swinging strike rate (SwStr%), chase rate on pitches outside the strike zone (O-Swing%) and contact rate on those pitches outside the strike zone (O-Contact%).

Alex's article persuaded me, and I downgraded Weaver's projection and consequently didn't draft him anywhere, owning him only in one NL-only keeper league. And sure enough, that pessimism from Alex's article was well-founded. Weaver's strikeout rate dropped to 19.9%, his BB% jumped from 6.8% to 8.9%, his HR/9 rate jumped from 1.04 to 1.25, and more importantly for fantasy purposes, his ERA skyrocketed to 4.95 and he was out of the Cardinals' rotation by the end of the season. He was included in the Paul Goldschmidt deal with Arizona and will likely get another shot to start there, but suffice to say enthusiasm for him has dropped, with his current NFBC clocking in at 339.14.

I thought it might be useful to see if we can find 2019's Luke Weaver - a pitcher with a sufficiently high enough K%, low enough SwStr% and an NFBC ADP in the top 150 - i.e. the first 10 rounds in a 15-team draft, one that follows their Main Event and the Draft Champions format that's available right now. Why the top 150? Because that's almost certainly going to be one of your top two starters, vitally important in a deep, no-trade format. If you whiff on one of those pitchers, that's a disaster that will prove to be a difficult recovery.

Here's a table of those top selected NFBC Starting Pitchers, along with their K% and SwStr%:

RkPlayerADPK%SwStr%
1Max Scherzer6.5734.616.2
2Jacob deGrom13.8132.215.1
3Chris Sale18.0538.415.8
4Aaron Nola22.6727.012.4
5Corey Kluber23.1926.412.0
6Justin Verlander23.7634.814.5
7Blake Snell27.0031.615.1
8Gerrit Cole29.1434.514.1
9Clayton Kershaw31.1923.911.0
10Trevor Bauer35.4830.813.3
11Luis Severino37.9028.212.4
12Walker Buehler39.3827.911.0
13Noah Syndergaard40.4824.113.6
14Carlos Carrasco40.7629.515.3
15Patrick Corbin50.8130.815.6
16James Paxton56.8632.314.3
17Stephen Strasburg57.1428.711.9
18Jack Flaherty63.2929.613.4
19Jameson Taillon63.9522.810.7
20Madison Bumgarner64.3819.89.2
21Zack Greinke65.3323.710.8
22Mike Clevinger69.4825.612.0
23German Marquez76.1428.212.6
24Michael Foltynewicz78.1927.210.3
25Jose Berrios81.1425.411.3
26David Price87.7124.59.6
27Miles Mikolas87.9018.19.7
28Zack Wheeler96.0024.110.7
29Kyle Freeland105.8620.59.0
30Charlie Morton109.2428.911.9
31Robbie Ray115.2431.412.9
32Luis Castillo115.2923.313.5
33Carlos Martinez121.1022.510.4
34Kyle Hendricks125.7119.89.2
35Chris Archer131.6725.413.1
36Masahiro Tanaka132.9025.014.1
37J.A. Happ143.2926.310.4
38Cole Hamels144.0023.312.1

I highlighted a few of the interesting pitchers from this list, that have either K%, SwStr% or decline concerns. Some of these I ignored like Kyle Freeland, Kyle Hendricks (or any other Kyle's you can think of - really, I'm not a first name-ist), or Miles Mikolas. They aren't strikeout artists to begin with, and for the most part their K% matches up with their Swinging Strike Rate. In many cases their discount is already implied, or at least you're not drafting them with an expectation of getting strikeouts above an average starting pitcher.

Clayton Kershaw (ADP: 31.19, K%: 23.9, SwStr%: 11.0)

It's arresting to see Kershaw not going in the first round, after being the consensus top starter year after year, but here we are after another injury-marred season. I wrote about Kershaw in July, speculating where he should go in 2019. At that point, his strikeout percentage hung at 25.1%, which already represented a huge decline. He strung together a number of good starts in that stretch, but his K% plummeted even farther, so that he ended the season 23.9%. To demonstrate how the SwStr% ties in with the K%, it's worth noting that rate dropped from 14.1% in 2017 to 11.0% in 2018. What's the next step? I suggested then that I wouldn't jump on him until the sixth round next year, which might be overstating the case, but it remains that I'm not going to be taking the plunge where he's going now, which is around the 2-3 turn. I'm at least waiting until somewhere in the 45-55 range, maybe later. Better to be a year too early than a year too late.

Walker Buehler (ADP: 39.38, K%: 27.9, SwStr%: 11.0)

I'm not going to lie, I was both surprised and somewhat disturbed to see Buehler return even near similar results to Luke Weaver. But before we hit the panic button, there are some significant differences between the two, who were born about 11 months apart. First, Buehler has a better fastball, both in velocity (96.2 mph vs. 93.2 mph for Weaver in 2017) and results (14.8 runs above average for Buehler, 2.6 for Weaver). Buehler has a better second pitch (his slider) than Weaver did in 2017 (his changeup), and also had a third pitch (his cutter) that was also above average, something Weaver did not have. Moreover his O-Swing% and O-Contact% were superior to Weaver's 2017 rates.

Jameson Taillon (ADP: 63.95, K%: 22.8, SwStr%: 10.7)

Taillon was a second-half surger, posting a 2.33 ERA after the All-Star break, fueled by him employing a slider for the first time, to great success. A big benefit to him using his slider was that it helped him combat a previously huge LH/RH split. Around the time he introduced his slider, lefties had an .847 OPS against him. By the end of the season, that had dropped to .737. Ironically, his overall success did not translate into more strikeouts - instead, his K% dropped from 23.3% to 22.2% after the break. The low SwStr% indicates that his relatively lower K% wasn't a fluke, however. I might be a little cautious in investing full price in that breakout.

Madison Bumgarner (ADP: 64.38, K%: 19.8, SwStr%: 8.2)

At his peak, Bumgarner's strikeout rate floor was 25% and peaked at 27.5% in 2016. Before his dirt bike accident in 2017, it was still at 25.0%. He finished 2017 at 22.4%, and dropped through the floor last year to 19.8%. Ironically, his fastball velocity pre-and-post accident were similar, right around 91 mph. But the effectiveness of both his fastball and slider have suffered, to the point where his fastball is no longer a plus pitch. In a related note, he's throwing his fastball less often, dropping from 43.0% of the time in 2017 to 34.2% of the time last year. He's mostly replaced that volume by throwing his curve more often.

Mike Foltynewicz (ADP: 78.19, K%: 27.2, SwStr%: 10.3)

Of the pitchers featured here, Foltynewicz fits the profile I'm worried about the most. His K% spiked from 20.7% in 2017 - a very average rate - to 27.2% last year, well above the league average. This despite a SwStr% that's relatively low, at 10.3%. That was an increase above his 9.4% 2017 rate. His chase rate and contact rate on pitches out of the zone also match up with what Luke Weaver did in 2017. The good news for Folty is the massive spike in effectiveness with his slider. The strikeout rate on his slider spiked to 42.4%, up from 30.9% in 2017. Not coincidentally, he threw his slider a lot more often last year, up from 21.2% in 2017 to 27.1% last year, most often at the expense of his sinker. Can his arm withstand throwing so many sliders? It's the key to whether he can stay successful.

David Price (ADP: 87.71, K%: 24.5, SwStr%: 9.6)

Eno Sarris is a national treasure, and his work should be feted appropriately. Price made some adjustments after a rough patch this summer, finished strong and then was a playoff hero. It's worth noting that after reaching the All-Star break with a 24.2% K%, Price came in with 27.7 and 26.0 K%'s in August and September after his adjustments. The dangerous aspect of Price's repertoire is that he is losing significant velocity on his fastball (though comparing 2017 to 2018 is a little skewed because he worked out of the bullpen for a good chunk of 2017), and he's throwing it less often - a trend we've seen with other aging pitchers. There's probably another drop coming, but Price has been able to soften the blow by adjusting on the fly.

Zack Wheeler (ADP: 96.0, K%: 24.1, SwStr%: 10.7)

I'm hesitant to draw too many conclusions about Wheeler's big season, because we have so little data to know what a healthy version of him should look like. That said, Wheeler's K% jumped last year, as did his SwStr%, from 9.1% to 10.7% last year. Wheeler threw harder last year, adding about one mph to both his four-seamer and his sinker, which could account for a lot of his success.

Carlos Martinez (ADP: 121.1, K%: 22.5, SwStr%: 10.4)

I don't know exactly what to make out of Martinez, and I'm mostly scared of him. The Cardinals intend to transition him back to the rotation, but they have plenty of alternatives, even after trading away Luke Weaver. I count nine potential starters, just among those who saw action with them last year - Jack Flaherty, Miles Mikolas, Martinez, Adam Wainwright, Michael Wacha, Alex Reyes, Austin Gomber, John Gant and Daniel Poncedeleon. Some of those options are obviously stronger than others, but the point remains - Martinez doesn't *have* to start for them if they're not convinced he's better in that role. He had a 25.0% K% as a reliever, 22.0% as a starter. His fastball dropped from 95.6 mph to 93.6 mph. Danger, Will Robinson, danger!

J.A. Happ (ADP: 143.29, K%: 26.3, SwStr%: 10.4)

It's rare to see a 36-year old set a career-high in K%, but here we are with Happ. Happ had a 26.3 K% last year despite a career 20.9% mark. Though he had a 2.69 ERA after the trade to the Yankees, his K% declined after the trade and his FIP (4.21) suggested he was fairly lucky after the deal. But ... Yankee Stadium actually plays to his strengths, lowering his likelihood of allowing home runs. Happ's 10.4 SwStr% actually represents a full point jump over 2017, so it's a good bet that strikeout regression will occur. But that's also priced in his ADP - nobody is really paying for his 2017 results.

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There's no such thing as a perfect predictive stat, but I've often found K% and SwStr% to be helpful. Keep in mind there are plenty of factors that aren't accounted for when looking at this list, such as was the case with David Price. Stats are necessarily backwards looking, so teams and players are also aware of potential shortcomings reflected by these stats, too. But hopefully this gives you some insight to your starting pitcher strategy for 2019.