Strikeout Rate Risers and Fallers - Buy or Sell for Week 7

Welcome back to the pitching strikeout rate risers and fallers article series! Each week we will take a look at two K% risers and two fallers, analyze what is behind those changes, and then decide if they are actionable. A pitcher can best control their fate by generating swings and misses, so this exercise holds particular importance for fantasy value. Understanding strikeout trends and the stats behind them can help you sort through all the noise and determine which pitchers are legit and which pitchers should be avoided.

This is the second week that we will be using RotoBaller’s K% Risers and Fallers premium Tool. This tool identifies players who are surging and falling in strikeout percentage over the last 30 days. The goal of this tool is to help you find pitchers who are showing improving or declining K%.

The tool will provide deeper insight as the season progresses and we get more data. At this point, we have about two weeks of additional data past the first 30 days of the season, so there are definitely some insights that we can draw. Let's get into it and see if we can't identify some buy-low or sell-high candidates!

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Strikeout Rate Risers

All stats current as of Sunday, May 12

Eduardo Rodriguez - Boston Red Sox

Season K%: 24.2%, Last 30 Days: 27.1%

Our first K% riser is one who has teased us with fantasy talent in the past but has not yet been able to put it all together. Eduardo Rodriguez has shown that he can post high strikeout numbers but has also shown a lack of command and a propensity for getting injured. His 4.53 ERA through his first 43 2/3 innings pitched leaves something to be desired, but he has seen a notable uptick in his strikeout rate lately. Could Rodriguez be about to take off after his early-season woes?

The 26-year-old allowed an unsightly 16 earned runs through his first four starts but has pitched much better in his last four, posting a 2.28 ERA and 1.18 WHIP with 25 strikeouts over 23 2/3 IP. A noticeable change from his first set of starts to his second is the use of his changeup. Rodriguez has a great changeup and has thrown it about 21% of the time this season. However, he has relied on it more in his last four starts, throwing it roughly 23% of the time. This has helped boost his strikeouts numbers, as Rodriguez has had a career-high 23.4% swinging-strike rate with the pitch.

Rodriguez's improved performance as a whole could be attributed to his improved pitch command. He has been able to locate his pitches better, leading to an impressive 26.6% hard-hit rate and a career-low 9.5-degree launch angle. However, his career launch angle is 14.2 degrees, so I am not ready to buy into his current launch angle. Further, his SIERA over his last four starts is 3.82, which, while it is certainly an improvement from his season ERA, is quite higher than his ERA in that time frame.

In sum, I would consider E-Rod to be a low-end buy-low candidate. He has made some improvements with his strikeouts lately, but the underlying stats send mixed signals. He is worth a speculative roster spot if you have room, but I would be afraid to give up any significant value or even potential value for him at this time.

Luke Weaver - Arizona Diamondbacks

Season K%: 27.2%, Last 30 Days: 30.7%

I wrote about our second K% riser a few weeks ago as an undervalued fantasy option and he has continued to impress since then. The 25-year-old is 3-1 with a 2.98 ERA, a 1.06 WHIP, and 50 strikeouts in 45 1/3 IP with the Diamondbacks this season. He has had good strikeout numbers throughout the season but has seen relatively better numbers over the last 30 days. He is still just 66% owned; should he be someone you should be targeting?

Weaver’s last two starts have both been gems; he allowed a single run over seven IP in each with eight strikeouts at the Rockies and six at home against the Braves. In the Rockies start, Weaver had some extra giddy-up on his fastball (95 MPH vs 94 MPH average for the season) and was able to generate five strikeouts with the pitch.

In his start against the Braves, Weaver utilized his much-improved cutter to get half of his strikeouts. Weaver only threw the pitch 4.7% of the time in 2018 with a poor 4.4% swinging-strike rate, but this season he has thrown it 14.4% of the time with a much-improved 10% swinging-strike rate.

Weaver has made many positive strides since joining the now pitcher-friendly confines of Chase Field. He has a career-high 10.7% swinging-strike rate overall and a 3.48 SIERA to support his ERA. He showed fantasy promise in 2017 and could be capitalizing on it now. I am buying his performance so far and think he should be owned in all but the shallowest of leagues.

Strikeout Rate Fallers

All stats current as of Sunday, May 12

Zach Eflin - Philadelphia Phillies

Season K%: 18.9%, Last 30 Days: 15.4%

Our first K% faller has never been much of a strikeout pitcher but has gotten off to a great start overall in 2019. Zach Eflin has started with a 5-3 record, a 2.47 ERA, a 1.02 WHIP, and 38 strikeouts in 51 IP. The 25-year-old's K% has dropped even lower in the last 30 days, which limits his fantasy ceiling, but can he still be a valuable fantasy starter this season? 

After digging into Eflin's advanced stats, I have doubts that his success this season has been legit. Eflin has tended to pitch to contact and he has done a decent job of that, allowing an average 11.5-degree launch angle with an exit velocity of 86.4 MPH. However, his .259 BABIP compared to a career .288 and his strand rate of 86% compared to a career 69.8% suggests that he has gotten lucky on his batted balls. His 4.22 SIERA also supports the notion that he has gotten lucky overall.

Fantasy players are buying into Eflin, as he is currently 65% owned. He has also had two great starts in a row, allowing one earned run over 16 IP. This makes him the perfect sell-high candidate. His numbers under the hood indicate that he will not continue to pitch as well as he has done, but with his recent success on everyone's mind, it is likely that he could be flipped for a consistent fantasy asset.

Jake Odorizzi - Minnesota Twins

Season K%: 26.1%, Last 30 Days: 23.5%

Our second faller has also gotten off to a career start, but unlike Eflin, he has high strikeout potential. Jake Odorizzi has a 2.32 ERA, a 0.94 WHIP, and 43 strikeouts in 42 2/3 IP. His K% has fallen a bit in the last 30 days thanks to a two-strikeout performance on April 22, but he has still been an effective fantasy starter overall to this point. What should fantasy players make of Odorizzi's start to the season?

Odorizzi's profile presents a mixed bag of evidence for his success. On the plus side, he has posted a career-high 12% swinging-strike rate, which could be attributed to an increase in fastball velocity (92.3 MPH vs 91.1 MPH in 2018, 13.6% swinging-strike rate vs 11.6% in 2018). He also has a career-low WHIP of 0.94.

On the other hand, his walk rate is too high (9.1%) and his .221 BABIP compared to a career .271 BABIP suggests that his WHIP will not hold up over time. Further, his 20.2-degree launch angle is way too high for comfort. His 0.42 HR/9 rate will not last with that launch angle, and his 4.26 SIERA supports that.

Overall, it is tough to make a firm call on Odorizzi. Fantasy players' decision to own him or not will depend on their risk tolerance. He has posted strong strikeout numbers even though they have dropped a bit over the past 30 days and he has achieved good results to this point. However, his underlying stats suggest that he is walking a fine line and could regress for the worse.

K-Rate Risers and Fallers - Premium Tool

Identifying top strikeout rate risers and fallers for each week can help you spot the best pickups before your competition. RotoBaller's Premium K-Rate Risers and Fallers tool has you covered every day. As thoughtful fantasy baseball players, we won't lead you astray. This tool will soon be active once we have a large enough sample size in the season to be considered reliable.

This type of data is available as part of our Premium MLB Subscription. Don't settle for basic stats and surface-level advice from other sites. RotoBaller brings you advanced statistics and professional analysis that you need to win your fantasy leagues and DFS games, because we're ballers just like you. We are your secret weapon!

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