Power Risers/Fallers for Week 13: Buy or Sell?

RotoBaller's Premium Power Surgers tool helps you identify home run risers and fallers to see who is worth adding or streaming In Week 13 of the 2018 fantasy baseball season.

Welcome to Week 13 of the 2018 MLB season and a new week of our investigation into the steepest power trenders in baseball, whether those trends are positive or negative.

As the season steamrolls through June, the window of opportunity to snag a surging slugger or to deal a down-and-out disappointment grows shorter with every plate appearance. Getting the jump on identifying the catalytic variables and telling trends in these player's recent offensive performances could be the key factor in the management of your roster in the summer months.

To do this, we'll be taking a look at the batting metrics that influence a hitter's power (Fly-Ball%, Pull%, Hard-Hit%, Exit Velocity) and determining whether you should buy or sell respectively on these surgers and strugglers. Since it's always best to wait and trudge through with the power play from players like Bryce Harper, Charlie Blackmon, Joey Votto, and Mookie Betts, we are going to be focusing on players who have seen a change in their power profile due to a change in batting metrics and has either warranted greater attention for waiver wire pickups or for a potential trade to cash in on what's left before it's too late.

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Power Risers

Mark Trumbo - (OF, BAL)

Mark Trumbo went from HR champ to down-and-out with a .686 OPS in 2017 for the Baltimore Orioles. In the last two weeks, he has caught red-hot fire with five homers and a slash line of .324/.375/.784 through 37 AB over that span of time. Does this mean that Trumbo is back in Silver Slugger form, or does it mean that he could be due for a regression after his recent offensive explosion?

Trumbo's plate discipline appears completely unaltered. His strikeout and walk percentages of 24.7% and 6.7% respectively are almost right on the dot with his career averages. He is also producing a 1.22 GB/FB ratio and 34.2% pull rate so far in 2018. While these figures are a little less than ideal for high-volume HR hitting, they don't deviate much from his career norm and thus they are of little concern because it was also his career norm to smack 25-30 long balls when given ample opportunity. The real difference-maker with Mark Trumbo in 2018 is his quality of contact.

While he is still hitting for more soft contact (19.2%) than is preferred, he is hitting for an impressive 12% more hard contact this season than he did in his woeful 2017 campaign, and is in fact hitting for his best hard contact rate of his career this year at 42.5%. This has translated to Trumbo crushing the ball to the tune of 400 feet on average per HR with a blistering 93.8 mph average exit velocity. That goes a long way in hitter-friendly Camden Yards and makes Mark Trumbo once again a powerful force to be reckoned with at the plate.

Yuli Gurriel - (1B, HOU)

In stark contrast to his days of hitting 25-30 HR in Japan and Cuba, Yuli Gurriel's peripherals may suggest that his total of 18 from last season for the world champion Astros may be his hard cap (at least in the MLB). After a pedestrian first couple of months in 2018 that included just one ball-gone-yard, Gurriel finally started to heat up in June with three homers and a slash line of .344/.372/.522 for the month. While three HR isn't exactly eye-popping, it is still optimistic for Fantasy Baseball Managers hoping he could once again make a push for 20.

Though, I wouldn't count too heavily on it. While Gurriel has posted a respectable 35.3% hard contact rate while keeping his soft contact low at 14.1% in June, he is still hitting more than half of his batted balls for medium contact in conjunction with a GB/FB ratio of 1.58 on the year. His pull rate of 45.8% is good, but isn't too serviceable when he is hitting grounders and medium contact batted balls with such high frequency. When taking his low strikeout percentage of 10.2% into account, it appears much more likely that Yuli Gurriel is a well-rounded offensive producer out of the deadly Houston batting order as opposed to a 20-25 HR option. He has only been hitting his homers 372 feet on average and at this rate, even his total of 18 HR from 2017 seems to be pushing it in terms of remaining expectations.

Jason Kipnis - (2B, CLE)

Two-time All-Star Jason Kipnis has looked rather pedestrian for the better part of two years now, and even in his peak seasons of the past, he only ever managed as many as 23 bombs in a full season. His staple actually used to be stolen bases and, now that he isn't going for them, his results with the bat are more important than ever for his individual value. In the past two weeks, Kipnis has seemingly turned back the clock to a happier time with three HR and a 1.043 OPS over 34 AB for the Cleveland offense that is near the top in the league.

Surprisingly enough, this could be one of Kipnis's best power seasons ever. While his soft contact frequency is flirting with the 20% range, his current rate of 37.1% for hard contact on batted balls is actually the highest mark of his career. His recent surge has also come along with a hard contact rate of 38.5% for the month of June alone. That translates to a decent amount of dingers when applied to his 0.83 GB/FB ratio. He has also shown decent pop with an average HR distance of 404 feet despite a slightly below average exit velocity of 88.2 mph.

While a few things don't create a whirlwind of excitement around Jason Kipnis such as his lack of stolen bases, his below-ideal pull rate of 34.4%, and his strikeout rate of 19.4%, those are hardly paramount to his demonstrated power this year. With Kipnis being widely available to Fantasy Baseball Managers at the moment, it is a sneaky little secret that he could be on pace to turn his newly found affinity for hard contact into a career-high HR total.

Kike Hernandez - (SS/2B/OF, LAD)

The Dodgers have had to survive over the last couple of seasons with the frequent aid from emergent players, and where would they be without Kike Hernandez lately? Hernandez got off to a slow start this season following his 2017 postseason heroics for Los Angeles but has been, dare I say, infuego over the last month. In fact, he has hit five HR with a 1.075 OPS in the last two weeks alone to push his homer total on the year to 13, which already shatters his previous career best.

Having said that, the future is foggy for Hernandez's power prospects. Despite his remarkable play during June he managed a rather concerning soft contact rate of 23.6% and a stagnant 29.1% for hard contact frequency. That doesn't read well, especially with an average exit velocity below the league average at 88.0 mph. His pull rate of 51% and GB/FB ratio of 0.72 lean well in the right direction, but his hard contact has to at least crack 30% for those peripherals to foretell of consistent long balls to come.

Kike Hernandez's overall offensive play has certainly been boosted by a 10% decrease in strikeout frequency from the first two months of the season to June, and his average home run distance of 400 feet suggests he is capable of clobbering a pitch when he gets a true hold of it. His hard and soft contact rates on batted balls is troubling enough though to warrant heavy trepidation for his long term prospects, especially for an infielder that has never posted more than eight steals in a minor league season. Enjoy his recent surge in the top ten Dodger offense, but Hernandez has coincidentally left a lot up in the air.

Power Fallers

Jeimer Candelario - (3B, DET)

Despite his recent two-week stretch in which he saw just one HR and a slash line of .171/.348/.286, the peripherals for the 24-year old Jeimer Candelario have for the most part looked increasingly more optimistic as the season has progressed. Before his very recent struggles the Detroit corner man had compiled two straight four HR months with respective OPS of .886 and .907 respectively.

Through the first three months of the 2018 season, while Candelario's walk percentage has steadily increased from 10% to 13.5%, his strikeout rate has also frighteningly gone from 22.5% in April to 30.2% in June. Over that same stretch of months his soft contact rate on batted balls went from a tolerable 16.5% to a highly inaccurate 26.9%. Though this increase in soft contact has come completely at the expense of his medium contact, as his hard contact has improved from 35.4% to 38.5%. His batted ball placement has also become more ideal for power hitting as his pull rate has ballooned all the way up to 57.7% and his GB/FB ratio of 1.42 for April has come significantly down to a rate of 0.72 for June.

Jeimer Candelario had never demonstrated elite power as a minor league player, and so this movement in both directions from both his plate discipline and batted ball power indicates he is still figuring out the approach at the plate best suited to his strengths. Striking out nearly a third of the time doesn't do any player too much good, but it is a good sign that the young gun is hitting with increased hard contact frequency. Now if he could just lower his soft contact below 20% once again, we could be a little more insured in his consistency and projection for the remainder of the season.

Joey Gallo - (3B/1B/OF, TEX)

Joey Gallo's problem isn't power. He has hit his 18 HR this year an average distance of 405 feet at a lightning-like speed of 95 mph in average exit velocity. Even as he has struggled significantly in the last 14 days with one dinger and a hideous .103/.257/.241 slash line, he has still been producing an incredible 60% hard contact rate on batted balls! This is in addition to other optimistic peripherals like his 46.7% pull rate and 0.60 GB/FB ratio in June. The demons that continue to haunt Joey Gallo appear in the form of whiffs, an MLB leading 113 whiffs to be exact. That's from producing strikeout rates of 42.6% and 41.3% from the last two months, although he has still been walking at a high frequency of 17.3% this month.

It is a big problem if a player isn't even giving himself a batted ball's chance in 60% of his opportunities on offense. Even when he is routinely cracking whatever pitches he does make contact with at a powerful clip. Joey Gallo isn't really a power faller this week, he is just a faller. You can't hit HR if you aren't making contact. The 24-year old highly touted Rangers prospect still has plenty of time to sharpen his mechanics at the big league level, and we already know what the future could hold from his 41 HR last year. On the other hand, this has always been the issue that plagued him, and it is a little concerning to see such little headway from him in this department despite the other things he is doing well with the bat. There are a lot of near .200 BA guys who can smack 25-35 homers in a given season, but Joey Gallo was supposed to be way more than that. He can't be anything more until he becomes a more complete and disciplined batter.

Mike Moustakas - (3B, KC)

Two-time All-Star Mike Moustakas is only on a slightly slower HR pace with his 14 knocked at this point in the season than he was last year when he crushed 38 homers, which was a career-high mark by a long shot, though in the last two weeks he has struggled to just one dinger and a .589 OPS. The good news is that the slump should be over soon, and when it is, Moustakas will come back with a powerful vengeance at the plate.

This month "Moose" has taken a walk 9% of the time while only striking out 14.6% of the time. While his plate discipline looks good, his power prospects moving forward look even better. Despite his recent struggles he has been able to produce hard contact on batted balls a whopping 45.6% of the time in June while hitting for a season-low soft contact frequency of 17.7%. With a pull rate of 42.5% and a 0.73 GB/FB ratio accumulated through the season's first three months, it is easy to see how Moustakas could so easily be back on the path to 30-35 homers by the end of the year. His average exit velocity of 90.1 mph and HR distance of 400 feet also sit above the league norm.

It is a huge downside that Mike Moustakas mans third base for one the worst offenses (and teams for that matter) in the MLB. While he has struggled lately, his hard contact can't be denied, and it should raise eyebrows that his contact on batted balls this season is so much higher than his previous career-bests from other successful power-hitting campaigns. Still being just 29 years old, though it may be hard to believe, we may not have seen the best yet from the Kansas City hot corner.

Danny Valencia - (1B/3B, BAL)

At age 33, Danny Valencia has quietly built up a reliable multi-year track record that would indicate that his sleepy level of well-rounded offensive success is no fluke, just business as usual. His dependable BA/OBP combo as well as three straight years of 15+ HR seems to have flown right under the noses of many Fantasy Baseball Managers. While he has continued to produce high-quality BA and OBP, he has only managed to smack one homer in the last two weeks for the cellar-dwelling Orioles.

Valencia routinely hits many more grounders than he does fly balls (he holds a 1.23 GB/FB ratio this season and a career average of 1.34) while also normally producing a pull rate north of 40% (he sits at 45.6% for 2018). Valencia has been hitting batted balls for hard contact 32.4% of the time this year. While that figure is by no means Herculean, it is higher than any mark he has produced since 2015. That is largely telling when considering his consistent mid-teens HR totals of the past few seasons. Not only that, his soft contact rate of 14.7% is his lowest rate since 2012. Valencia makes a ton of medium contact, but even so has an average exit velocity of 92 mph and a nice average dinger distance of 413 feet.

As discussed before, that kind of pop goes a long way in hitter-friendly Camden Yards, whether it be for a near last placed offense or not. Danny Valencia's value in terms of BA and OBP is well known, but with 50 combined yard balls in the three seasons before 2018 and power peripherals that indicate he may be at his best in this campaign, he has plenty of value for Fantasy Basbeball Managers in search of a widely available, well-rounded sleeper.

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