Ben Ruppert investigates Week 13 trends in SP strikeout rates (K%). These MLB risers and fallers present buy and sell opportunities for your fantasy baseball team.

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 in week 13, 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

Jordan Zimmermann, Detroit Tigers

Season K-Rate: 16%, Last 30 K-Rate: 21%

It’s been another tough season in Detroit for one Jordan Zimmermann. Last season he signed a five-year, $110 million-dollar contract with the Tigers. He proceeded to throw only 105 1/3 innings (18 starts), holding a 4.87 ERA and 1.37 WHIP with a career-low 14.7% K%. Considering his ERA only topped 3.26 once over the prior five seasons, it was viewed as just an off-year for him. This season however, the results haven’t changed. So far over 86 1/3 innings pitched (15 starts), he holds a 5.53 ERA and 1.49 WHIP, and his BB% has reached a career-high 7.5%. His strikeout rate has risen of late, but will we see an improved Zimmermann moving forward?

During the month of June he has made some improvements. Over his past five starts he holds a 3.82 ERA and 1.37 WHIP, and threw four straight quality starts before his latest outing when he gave up five runs. His recent success can be pinpointed to his newfound slider grip, which has given the pitch new life. His slider has historically been his best pitch, but he got away from how he used to grip it after an injury-plagued 2016. When he wasn’t seeing the results he liked with his new slider grip, he reverted back to his old ways. By watching old video, he realized his arm slot was changing slightly when he threw the pitch and his fingers were more on the side of the ball. The adjustment has allowed him to throw his pitches more consistently, and keep hitters honest when he throws his heater. Below you will see a start he made back in April, and his slider location is all over (all charts courtesy of Fangraphs):

Another example here is his start on June 14. You can see he gets his pitch in the zone more, and hits the edges of the zone.

While the slider improvement is notable, is still isn’t enough to make him a viable fantasy option. After his four straight quality starts, he threw a clunker against the lowly Padres in San Diego. The pitch has helped him regain streaming potential, but if anyone is buying his improvements I would be selling him for someone with a higher ceiling.

Verdict: Sell

Daniel Norris, Detroit Tigers

Last 30 K%: 25%, Season K%: 21%

We’re not done with struggling Tigers pitchers: next up is Daniel Norris. After outpitching his peripherals the past two seasons, things have caught up to him this season. Over 81 innings (15 starts) in 2017, he holds a 5.00 ERA and 1.62 WHIP. In 2015 and 2016 he posted a combined 3.55 ERA and 1.31 WHIP over 129 1/3 total innings. Despite the varying results, his FIP/xFIP over all three seasons have been in the low-to-mid fours. Norris has been unable to get control his pitches this season, leading to a career-high 9.5% BB% and a decreased K% from last season (23.5% to 21.0%). His ERA for June is 6.08, but his strikeout rate has increased. The question is, will he be able to figure things out and out-perform his peripherals again this season?

Norris has been getting a bit unlucky this season with a career-high .355 BABIP, compared to his .312 average. Unfortunately, he’s not doing himself any favors to get that number lower. His inconsistencies on the mound have shown us he can be dominant at times with his stuff, but also struggle to throw strikes. Things begin with his arm slot, which can vary from time to time as seen below:

When his arm slot varies it changes the break on his pitches, causing the inconsistencies. The results have him throwing less first-pitch strikes, and less pitches in the zone overall from last season. His swing % is down, which has led to the increase in walks, and his contact % is up. So when he does throw it in the zone, he’s catching too much of the plate; he’s allowed a .292 BAA this season. When you need to catch up in the count after not throwing first-pitch strikes, you don’t have the wiggle room to pick corners which gets him into trouble. Hitters are hitting the ball off of him harder than ever with a hard hit % of 40.2%, and they are pulling for power with a 43.4% pull %.

Norris has all the tools to be a solid fantasy starter, but inconsistencies have plagued the young pitcher this season. He has shown he can do it in the past, so keep an eye on him as the season progresses. Until he fixes these issues, he shouldn’t be relied upon for fantasy.

Verdict: Sell

K-Rate Fallers

Jacob deGrom, New York Mets

Last 30 K%: 19%, Season K%: 28%

With injuries being sustained left and right for the New York Mets, it’s been comforting knowing they can give the ball to Jacob deGrom every fifth game with a great chance to win. The results for him this season have been mixed, but lately he seems to be figuring things out. On the season, he holds a 3.71 ERA and 1.27 WHIP, with a 27.8% K% and a 9.1% BB%. His strikeout and walk rates are both career-high’s, along with his sky-high 17.3% HR/FB. After allowing 15 runs over a two start stretch, he has thrown three straight one-run outings (only two of which were earned) while going at least eight innings in each start. His strikeouts are down a smidge, but those results are stellar. Can he maintain this pace and limit his walks?

According the deGrom himself, one of the main reasons he fell into that two-start funk was because the Mets shifted to a six-man rotation for a few weeks and it messed with his schedule. The results obviously were not pretty, so he reached out to former ace/closer John Smoltz for advice. He suggested adding a second bullpen session in between starts, something he did for 10 years in the majors. deGrom had done this in the past , but has not been this season. The extra work allowed him to regain form and get back on top of the ball, which helped him re-find his consistency on the mound. His stuff has never been the issue; he currently sports a career-high 14.4% SwStr%, a career-low 70.3% contact %, and his fastball velocity is back up after being slightly down during last season's injury plagued year.

While his stats are slightly inflated, it is worth buying deGrom even at full price. He is pitching like a bona fide ace, even if his walks are up a bit this year. His HR/FB should decrease moving forward, and even if his strikeouts fall a small amount he has still been pitching well enough to dominate (.234 BAA, 3.86/3.48 FIP/xFIP). As long as he remains healthy (unlike the rest of the Mets pitching staff), he will be a borderline top-5 to 10 fantasy arm. Buy if anyone is selling.

Verdict: Buy

Marco Estrada, Toronto Blue Jays

Last 30 K%: 20%, Season K%: 26%

We’ve seen the best, and now hopefully the worst of Marco Estrada so far in 2017. Over 68 2/3 innings in April and May, Estrada compiled a 3.15 ERA and 1.11 WHIP while looking like one of the better arms in the league. Then when the calendar flipped to June, everything unraveled. Over 23 1/3 innings, he holds a 10.03 ERA and 2.19 WHIP. Opponents went from hitting .225 off of him through the first two months to .374 during June. On the season he now sports a 4.89 ERA and 1.38 WHIP, which is a far cry from his career 3.30 ERA and 1.08 WHIP in a Blue Jays uniform heading into the season. The question is, can Estrada work his way back form, or is he back to pitching like he did in Milwaukee?

Estrada was able to out-pitch his FIP/xFIP each of the past two seasons, but this year things have flip-flopped. His FIP is currently below four for the first time since 2013, which is due entirely to his increased K% (up to 25.6% this season) and decreased BB% from last season from 9.0% down to 7.0% this season. His tidy 3.64 K/BB has also unfortunately come with a decreased infield fly ball % (IFFB%) of 10.7%, down from 16.8% last year. His HR/FB is also up dramatically to 12.4% this season. Estrada hasn’t been allowing any more fly balls or grounders than usual, but hitters are clearly getting better pitches to hit this season. What is he doing differently? His changeup is regarded as his best pitch, and this season he has upped the usage of it from 28.6% last season to 36.2% at the expense of his cutter and curveball. The change has still been an excellent pitch; however the over-reliance on it has allowed hitters to sit on it more than in years past. He’s already allowed six HR on the pitch this season after allowing only 15 against it over the previous two seasons. He will need to retool his pitch selection if he wants to regain his form.

The stuff is still there for Estrada, an over-reliance on one pitch seems to be his downfall this season. If he can get back to mixing in his breaking pitches just a bit more, he will be able to keep hitters honest at the plate. There is no reason we can’t see Estrada revert back to his usual form; this seems like a good time to buy low on him if you can afford to wait for him to right the ship.

Verdict: Buy

More Risers and Fallers

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