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.  The tool is for Premium subscribers only, and can be found here. 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.

K-Rate Risers

Luis Severino, NYY

2016 K-Rate: 21.2%, 2017 K-Rate: 35.5%

The difference between 2015 and 2016 for Luis Severino wasn’t much. He struck out the same number of hitters, walked the same number, and threw the same types of pitches. However, his BABIP rose by nearly .060 points, causing his ERA to skyrocket by nearly three runs. Hitters had figured him out, and he needed to make some changes if he wanted to stick around in the majors. After working with Pedro Martinez in the offseason, one change is immediately noticeable: his changeup usage. The change has led to his other pitches becoming more valuable, and a 12.15 K/9, 0.90 BB/9, and a 3.12/1.71 FIP/xFIP through three starts.

Severino has thrown his changeup 17% of the time this season compared to 8% last season. The increase has meant a decrease in his slider usage by 8%, however the effects it has had on both pitches is eye-opening. His changeup is currently sporting a 53.8% strikeout rate, and opposing hitters are hitting .000 against it. The slider has been nearly as good, with a 50.0% strikeout rate and a .120 batting average against. These improvements have led to a rise in swinging strike rate, which is up to 11.3%, and his contact rate has dropped 6% to 72.6%. His hard and soft contact rates are both trending in the right direction from last season, currently sitting at 23.4% each. His pitch movements and velocities haven’t changed much, so these positive strides can be attributed mainly to his changes in pitch selection.

While his .233 BABIP is bound to rise, his HR/FB rate of 26.7% should drop closer to his career average. I’m buying the changes Severino has made; he has a chance to be a top-30 pitcher this season.

Verdict: Buy

Jason Vargas, KC

2016 K-Rate: 23.4%, 2017 K-Rate: 31.1%

Jason Vargas underwent Tommy John surgery after nine starts in 2015, putting a severe damper on his chances to make any impact at all in 2016. He made it back for three starts last season, and did surprisingly well over 12 total innings. He held a 2.25 ERA and 0.92 WHIP, with an 8.25 K/9 rate. Early on this season the success has followed him; through three starts in 2017 he has a 0.44 ERA, 0.77 WHIP, and a 10.02 K/9. For his career, Vargas holds a 4.11 ERA, 1.30 WHIP, and 6.00 K/9. What, if anything, is Vargas doing differently since his Tommy John surgery?

Well, there aren’t too many changes in his pitching profile. His pitching velocities and movements are all similar to his career, however his changeup this season has been even more immaculate this season than normal. His changeup has always been his best pitch, but this season his swinging strike rate on the pitch is through the roof. A career 18.5% SwStr% is very good, but this season that number is at 31.0%. His ground ball rate is higher than ever before at 53.1%. He has thrown his changeup and sinker a little more than usual to begin the season, so it could be just a matter of Vargas finally finding the right combination of his pitches to use in a game. He has also been attacking the zone more; his Zone% is up to 51.9%, the highest it’s been since 2007. This change has led to his walk rate dropping to a career-low 2.7%, much higher than his 6.8% career rate.

What should we believe with Vargas? Is he the next pitcher to figure things out late in his career, or is this a blip on the radar?  His BABIP is at his career norm, and his FIP/xFIP support his start so far.  His 0.0% HR/FB rate is bound to rise though, and his LOB% of 93.8% is bound to drop. Vargas should be added, as this could be one of the better years of his career. However, I would be trying to sell soon while his value is near its peak.

Verdict:  Sell

K-Rate Fallers

Jose Quintana, CWS

2016 K-Rate: 21.6%, 2017 K-Rate: 17.5%

Over the first five seasons of his career, Jose Quintana has been the model of consistency. He has thrown 200 innings each of the past four seasons, with a K/9 between 8.00 and 7.38 each of those seasons. His BB/9 has been nearly as consistent, and his ERA has been in the mid to low 3.00 range each season. This season, however, things have gotten off to a rocky start. In his first three starts, Quintana has a 6.75 ERA and a 1.62 WHIP. His 7.27 K/9 is still close to his career average, but his BB/9 has ballooned to 4.67. In his first start of the season he allowed three HR, which has boosted his HR/FB rate to 16%.

Looking a little deeper, his pitch velocities and movements are nearly identical to his career rates, so nothing to see there. His BABIP of .288 is actually a little lower than his career average, so he’s not necessarily getting unlucky. What has been happening to Quintana is that opposing hitters are swinging at his outside pitches at a lower rate this season than at any year of his career, and his first strike rate is down this season to his rookie-year levels. The point being, he’s throwing balls and this season hitters aren’t taking the bait. Quintana should be able to rebound, seeing as this isn’t the first time he’s struggled out of the gate. In 2015, Quintana posted a 6.55 ERA in April, and ended the season at 3.36.

He may be down now, but Mr. Consistency will make things right if you give him some time. Quintana looks like a strong buy-low while his value is about as low as it can get.

Verdict:  Buy

Kyle Hendricks, CHC

2016 K-Rate: 22.8%, 2017 K-Rate: 18.8%

Fresh of finishing third in the NL Cy Young award voting, Kyle Hendricks had big expectations for himself heading into 2017. Fantasy baseball owners however, saw some regression coming after last year’s ridiculous 2.13 ERA campaign. Though we expected it, I don’t think many saw regression hitting him this hard. Through three starts, Hendricks holds a 6.19 ERA, 1.38 WHIP, and a measly 8.7% K:BB ratio. He is drawing a similar amount of ground balls compared to last season, but his strikeout rate and swinging strike rate are both at career-low’s right now.

The main cause of concern has to be his dip in pitch velocity. All of his pitches are down, but everything starts with his fastball being down over 2mph. For his career, he throws about 88mph, but this season he is down to 85.2mph. The loss in velocity has caused a decrease in swing strike rate to all of his pitches, and hitters are making more solid contact on him compared to last season. If he can work to get his velocity back up, he should see some major improvements in his results (not to the tune of last season’s numbers, but still improvements). April has statistically been the worst month for him in his career, so this could just be a blip in the radar for Hendricks that were noticing more now since we drafted him so highly.

Hendricks won’t have a repeat of last year’s stellar numbers, however I do believe he will have better outings moving forward. Even if he has a year more like 2015 (3.95 ERA, 1.16 WHIP), there is still plenty of value in that. He is a more risky than Quintana, but this is a good time to buy Hendricks low before he figures things out.

Verdict:  Buy