Strikeout Rate Risers and Fallers - Buy or Sell for Week 23

Welcome back to the strikeout rate risers and fallers series for Week 23! 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.

The players in this article were chosen 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%.

Most leagues are now into the fantasy playoffs, so every start counts. To benefit fantasy players the most at this time, I will write this article a little differently than I have done for most of the season. I will discuss two strikeout rate risers who are not widely owned and may be potential streaming options; I will then discuss two strikeout rate fallers who are widely owned and may be potential sits in their starts this week. Trends are helpful over the course of the season, but fantasy owners are only worried about the next week at this time, so let's get going!

Strikeout Rate Risers

All stats current as of Sunday, September 1

Jordan Zimmermann - Detroit Tigers

Season K%: 17.1%, Last 30 Days: 25%

Our first K rate riser has actually been fantasy irrelevant for most of the season. Jordan Zimmermann has a poor 6.24 ERA and 1.42 WHIP on the season. However, he has been much better over the past 30 days (3.27 ERA, 0.77 WHIP, 25% K rate). Zimmermann is currently owned in just three percent of Yahoo leagues; could he be a sneaky pickup for next week?

Zimmermann found success in August by switching up his pitch usage. He actually used his slider more than his fastball (31.9% vs 27.8%), the first month that he has done so. Hopefully this trend will continue, as Zimmermann allowed a .233 batting average with the pitch and saw an uptick in strikeouts. He also managed to avoid hard contact, thanks in part to his improved control.  He allowed a mere .211 BABIP in August and had a solid 3.54 SIERA.   

It looks like signs are pointing up for Zimmermann and he has a two-start week, making him even more intriguing. His matchups are tough (against the Twins, at the A's), but he pitched well in his last three starts which were tough (at the Rays, at the Astros, against the Indians). While I certainly wouldn't consider it ideal, I think that Zimmermann could be streamed this week in points leagues for those willing to look past his season stats.     

Mike Montgomery - Kansas City Royals

Season K%: 18.4%, Last 30 Days: 25.8%

Our second K rate riser has been fantasy relevant in the past and could be useful this upcoming week. Mike Montgomery has a mediocre 4.66 ERA and 1.57 WHIP this season, but has been much better lately, posting a 2.45 ERA, 1.30 WHIP, and 25.8% K rate over the last 30 days. At 18-percent ownership, could he too be a useful streamer?     

While his numbers overall have indeed been better, Montgomery's K rate is bloated thanks to a 12-strikeout performance against the Tigers. Montgomery took advantage of a solid matchup, but this was not the only reason his numbers look better. Montgomery has mixed his pitches well all season, but he relied mostly on his cutter in August, which he generated a .115 batting average against and has managed a 14% swinging-strike rate with on the season. He also relied more on his changeup, which has also been a good swing-and-miss pitch (13% swinging-strike rate).

Montgomery seems to be firing on all cylinders right now and has a great matchup against the Tigers this week. He dominated them in his last start against them as mentioned above, so I would have no problem picking him up and using him in both points and roto leagues this week.

Strikeout Rate Fallers

All stats current as of Sunday, September 1

Zack Wheeler- New York Mets

Season K%: 23.2%, Last 30 Days: 14.4%

I wrote about our first K rate faller last week, saying that I was hesitant to start him given his recent performance. Zack Wheeler actually turned in a strong start against the Phillies, pitching six innings of one-run ball with four strikeouts. However, his K rate over the last 30 days is still at a poor 14.4%, so should fantasy owners have the same concerns they did last week?

Much is the same as last week in terms of Wheeler's overall performance the last 30 days. His ERA has been good at 3.41, but everything else has not been promising. Wheeler has a poor K rate, a 1.41 WHIP, and a 5.25 SIERA. These numbers echo his season-long marks, which have been disappointing.

Wheeler will face another tough matchup at the Nationals this week and, like last week, I wouldn't feel great starting him. I would understand owners starting him given his potential, especially in points leagues, but would hesitate to start him in roto leagues depending on where teams are in terms of standings.

Caleb Smith - Miami Marlins

Season K%: 28.7%, Last 30 Days: 20.5%

Our second K rate faller also made this article last week given his recent struggles. I had said that Caleb Smith had been inconsistent lately but suggested starting him given his two-start week. This turned out to be a big mistake, as Smith allowed 11 earned runs in those starts. Even worse, his K rate has continued to fall over the past 30 days to a pedestrian 20.5%. Smith has been a useful fantasy option for most of the season, so should fantasy owners trust him this week? 

The drop in strikeout rate lately can still be attributed to inconsistent command.  Smith has allowed 11 home runs and 16 walks in his last six starts. His strikeout rate isn't awful by any means, but he'll need to find his command again to be successful, regardless of who he faces.

Smith's recent performance certainly does not inspire confidence, but he does face a strong matchup against the Royals. In this instance, I would go with the matchup and Smith's upside and start him, despite his recent struggles.

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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