We’re constantly trying to come up with new features that will help you dominate your fantasy leagues. Last year, we built a tool that identifies the biggest trends in a pitcher's strikeout rate over the last thirty days. With our sample size being so small this early in the season though, we will look at the difference between pitchers' final 2016 K-Rate and their current K-Rate through two to three starts.

Missing bats is the #1 way a pitcher can control his own fate. If hitters make contact, the pitcher is largely at the mercy of the atmosphere, the weather, the ball park, the ability/work ethic of his fielders, and sometimes just sheer luck. This is ultimately why strikeouts are so important. By looking at pitchers with positive trends in their strikeout rate, we can spot improving or declining pitchers. If the K-rate is improving, but the ERA and WHIP are less than ideal, it can present a buying opportunity. On the flip side, you may want to sell a pitcher with a declining K-rate, if he wasn't supposed to be that good to begin with.

This particular article will focus on two strikeout rate risers and two fallers, and make an attempt to determine how you should treat each pitcher.

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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.

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K-Rate Risers

Gerrit Cole, Pittsburgh Pirates

Season K-Rate: 24%, Last 30 K-Rate: 30%

Gerrit Cole took a big step in his development in 2015, decreasing his walk rate of 7.0% from the season before to 5.3% and his ERA from 3.65 to 2.60. Big expectations were placed on him last season, only to have nagging injuries bog him down the entire season until he was shut down with elbow inflammation in September. A full offseason allowed Cole to heal up for 2017, and after a slow start he has begun to pick things up. He allowed eight runs in his first two starts with only six strikeouts in 11 innings. In his next five starts (32 innings), he’s allowed only seven runs while racking up 36 strikeouts.

The biggest change Cole has made this season is the use of his changeup. For his career he has used the pitch about 4% of the time, with decent results. This season it is up to 13%, and it has arguably been his best pitch this season. The charts below show his changeup location over his first two starts, versus where he has been in his five starts since (courtesy of Fangraphs).

When he locates the pitch low, hits either miss it or make weak contact. Hitters are batting .083 against it, with a swinging strike rate (SwStr%) of 15.1%, the second highest of any of his pitches (slider, 18.5%). The pitch has helped balance Cole’s 96mpg heater, which is allowing a career-low .243 BAA and 85.1% contact %.

Cole has been pitching like the stud we saw in 2015, rather than the injury-laden player we saw last season. If any owner is selling Cole, snatch him up and enjoy the season-long production.

Verdict: Buy

Patrick Corbin, Arizona Diamondbacks

Season K-Rate: 19%, Last 30 K-Rate: 22%

Patrick Corbin has had some ups and downs since his return from Tommy John surgery. After his return in 2015 he surprisingly saw his strikeout rate rise and walk rate fall, leading to a 3.60 ERA career-high 8.26 K/9 over 16 starts. With expectations up in 2016 Corbin saw his walk rate spike up (which we expected to happen in 2015) and his strikeout rate return to his career average. An increased HR/FB led to a 5.58 ERA 24 starts, leading to him spending some time in the bullpen. He fared better in that role, and earned a chance to start again this season. Through seven starts this year he holds a 3.89 ERA and a 12% K-BB%.

Corbin is back to throwing his slider as his secondary pitch, something he did in 2015 but avoided in 2016 predominately using his fastball and two-seam fastball. The slider is excellent; it has held hitters to a .183 BAA, and is his only pitch with a double-digit SwStr% at 22.1%. The increase in sliders means Corbin doesn’t need to try to get hitters to chase his fastball, which has helped lower the BB% on both of his fastballs. Hitters are still hitting .375 off of his four-seam, so he still has some work to do there. However, his hard contact is down from 38.5% last season to 30.2% this season, meaning hitters are making less-quality contact on him when they do.

His current strikeout % of 18.9% is right in line with his career averages, and his 6.9% BB% is still high, but it is much improved from last season’s 9.4%. Corbin’s FIP/xFIP are both at 3.99, which support his current production. He looks to be back in pre-Tommy John form, so while he won’t rack up a ton of strikeouts he can be a sub-4.00 ERA pitcher all season with his rediscovered slider usage.

Verdict: Buy

K-Rate Fallers

Dylan Bundy, Baltimore Orioles

Season K-Rate: 16%, Last 30 K-Rate: 13%

Dylan Bundy’s early season results have fantasy owners excited, confused, and concerned. On the surface, things look great for the former fourth overall selection. Through seven starts he has thrown seven quality starts with a 5-1 record, a 2.17 ERA, and 1.05 WHIP. Given his pedigree, this is enough reason to be excited for the future as an Orioles fan. However, looking a bit deeper we see some concerning statistics. His strikeout rate is a mere 15.9%, his BABIP is at .256, and his FIP/xFIP rest at 3.44/4.67 respectively. All of those numbers indicate some regression is coming for Bundy, the question is how much.

Velocity continues to be an issue for Bundy, who claims it is a non-issue. He was in the bullpen for the beginning of last season, but for the season averaged 94mph on his heater. This season it is down to 92mph, and hitters are hitting .293 against it versus .279 last season (velocity chart courtesy of Fangraphs).

The slider he has re-introduced has been electric, with a 23.4% SwStr% and a 58.4% contact%, both are far and away his best numbers for any pitch. Even with this punch-out pitch, he hasn’t struck out more than three hitters in four straight starts. For a pitcher who isn’t missing many bats, the best way to get people out is to induce weak contact on the ground. His GB% is at 31.3%, which is among the worst rates in the majors for starters. His hard and soft contact rates are close to his career averages, so he isn’t inducing a ton of weak contact this season compared to last season.

Bundy is limiting his walks and challenging hitters this season, which so far has been great, but isn’t ideal for sustained success. With his BABIP, HR/FB%, and ERA all bound to rise, this is the perfect time to sell Bundy while his value is at its peak. He may have a good season overall, but he will not keep up THIS level of success.

Verdict: Sell

Kendall Graveman, Oakland Athletics

Season K-Rate: 18%, Last 30 K-Rate: 14%

Much like Bundy, we have another starter here who’s gotten off to a fast start this season with low strikeout numbers. Kendall Graveman has made six starts this season, holding a 3.67 ERA and 1.19 WHIP. Outside of a nightmare start in Minnesota (3 1/3 innings, six earned runs), Graveman hasn’t allowed more than two runs in any of his other five outings. He has a 17.9% K% for the season, but has struck out more than four hitters only once in his past four starts.

At 26-years of age it isn’t crazy to think he can take a step forward this year, but his current 6.55 K/9 is higher than his 5.65 career average as it is. Given there isn’t much different about his pitching profile it seems unlikely he would make any huge jump in his strikeout rates. His career .291 BABIP is a little lower than the league average, but this season it is even lower at .265, so that number is bound to rise a bit. He is allowing just as much contact this season as he has in the past, but his hard hit % is at a career-high 35.9%. With batters making all kinds of quality contact against him, it is bound to catch up with him over the course of the season.

Graveman’s FIP/xFIP are at 4.51/4.46 respectively. He’s out-pitched these peripherals in each of his first two seasons, but has held an ERA over 4.00 each season. Graveman can be a useful in spots for fantasy purposes, but ultimately I would be selling him if anyone is buying.

Verdict: Sell

More Risers and Fallers

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