Strikeout Rate Risers and Fallers - Buy or Sell for Week 19

Connelly Doan identifies pitchers whose impressive and underwhelming strikeout rates could make them worth adding or dropping in fantasy baseball for Week 19.

Welcome back to the strikeout rate risers and fallers series for Week 19! 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%.

Many leagues are likely past their trade deadlines, but it is still important to pay attention to how your pitchers are doing as well as how pitchers who may be available are doing. For this article, I will focus on pitchers who could be out on the waiver wire and may be of fantasy intrigue. Let's get going!

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Strikeout Rate Risers

All stats current as of Sunday, August 4

Daniel Norris - Detroit Tigers

Season K%: 19.9%, Last 30 Days: 27.9%

Our first K rate riser hasn't stood out as a reliable fantasy option this season but has shown an uptick in K rate over the past 30 days and is just three-percent owned in Yahoo leagues. Daniel Norris currently has a 4.67 ERA, a 1.40 WHIP, and a 19.9% K rate. However, is he worth streaming down the stretch given his improved strikeout numbers?

Unfortunately, there is not enough evidence for me to think Norris is a sneaky add. His last five starts came in two chunks; he allowed 11 combined earned runs against the White Sox and Indians and then allowed a combined three earned runs in his last three starts against the Blue Jays, Mariners, and Angels. Overall, he had a 4.85 ERA and 4.30 SIERA during that time. The mixed results against a mix of opponents make it difficult for me to buy into Norris, despite his impressive K rate over those starts. There is not enough there for me to buy a legitimate change in his game.

Norris has never really been a fantasy contributor and there is not enough here to warrant attention yet. His next slated start is a favorable matchup against the White Sox. If he can put forth a good showing then, that would make four straight solid starts, which would merit some attention. Given the relatively weak division he pitches in, Norris should see plenty of good matchups for the rest of the season. That, combined with another couple of encouraging starts would be enough for me to consider streaming him down the stretch in deep leagues.   

Aaron Sanchez - Houston Astros

Season K%: 18.9%, Last 30 Days: 23.7%

Our second K rate riser has been a fantasy disappointment the past several seasons but just got traded to a very competitive team. Aaron Sanchez has upped his K rate over the past 30 days to a respectable 23.7% and has upped his fantasy intrigue by joining the Astros' rotation. Sanchez is currently owned in just 34% of Yahoo leagues, so could he be a nice pickup for the fantasy playoffs?    

Sanchez's overall numbers haven't been anything special over the past 30 days; he has posted a 4.26 ERA, 4.19 SIERA, and 1.20 WHIP in his last six starts. In terms of the K rate boost, Sanchez can thank his outlier start against the Rays in which he posted 10 strikeouts, thanks mostly to his curveball (14.8% swinging-strike rate, 93rd-percentile spin rate).

The other thing that stands out is, of course, his last start, which was his first in an Astros uniform. Sanchez pitched six no-hit innings with six strikeouts and helped with a combined team no-hitter. The Astros are a better team than the Blue Jays, and the question becomes how much can the new team potentially help Sanchez?

I wouldn't mind taking a gamble on Sanchez if I had a roster spot, if not just to take him away from another team in case he continues to pitch well with the Astros. I would only stream him in favorable starts and would like to see a few more starts before trusting him, but think he has a decent chance of being serviceable as a streamer.

Strikeout Rate Fallers

All stats current as of Sunday, August 4

Martin Perez - Minnesota Twins

Season K%: 19.8%, Last 30 Days: 15.1%

Our first K rate faller has had an ok season overall and has been useful in fantasy at some points. Martin Perez is currently 8-4 with a 4.58 ERA, 1.40 WHIP, and 19.8% K rate. However, that mark has fallen even further to a lackluster 15.1% in the last 30 days. He is out there in plenty of leagues (30% owned in Yahoo leagues), but should fantasy owners be looking to stream him?

The last five starts have not been kind to Perez. He has managed a bloated 6.00 ERA, 1.52 WHIP, and 4.78 SIERA. His command has been an issue and it has clearly affected his strikeout rate. Overall, Perez has never been much of a strikeout pitcher (career 14.7% K rate), so it would be unreasonable for fantasy players to expect it. Further, Perez actually has an excellent batted-ball profile this season (85.2-MPH average exit velocity, 29.9% hard-hit rate, 8-degree launch angle), yet has posted mediocre results. I would have been skeptical of this earlier in the season and would expect some positive regression, but, at this point in the game, I'm not sure I would be willing to bet on it.

Perez does pitch for a competitive team in a relatively weak division, so he's not the worst streaming option. However, given his recent performances, I would rather roll the dice on the two players I mentioned above over him for a spot start.

Adrian Houser - Milwaukee Brewers

Season K%: 24.4%, Last 30 Days: 20.9%

Our second K rate faller is currently owned in just five percent of Yahoo leagues but has put up decent numbers this season. Adrian Houser has a 4.24 ERA and 24.4% K rate over 63 2/3 IP this season, but his K rate has fallen some over his last 30 days. Could Houser actually be a nice streaming option?

The difficult thing here is that Houser only has nine starts this season and he has been inconsistent in them. Only one of his last four starts has gone well; he has allowed 13 earned runs in the other three. He has still managed almost a strikeout an inning in those starts, but he hasn't managed strong-enough results to make me feel comfortable.

That being said, the sample size is small and he was great in his Triple-A starts this season, plus he pitches on a good team, so I would be willing to use him as a streamer against favorable matchups only so long as he continues to get starting opportunities.

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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