Power Risers/Fallers for Week 25: 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 25 of the 2018 fantasy baseball season.

Welcome to Week 25 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.

We have somehow blown by into mid-September, which means the homestretch of 2018 is upon us. Most fantasy baseball leagues have already had their trade deadlines come and go, and the only decisions left for managers to make in terms of personnel are whether players are worth the AB they are receiving and whether a player is worth adding for a postseason push. 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 season's final 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

Kevin Kiermaier - (OF, TB)

Despite his overall sub-par offensive performance this season, Kevin Kiermaier has been doing a lot more on the field lately than making catches that defy the laws of physics. Over his last 73 AB he has had his best run at the plate all year with three HR and a slash of .329/.367/.630 and still grabbed two bags, bringing his season total to ten. Better late than never I suppose considering that he failed to produce an OPS for a month above .682 prior to September, where he is now boasting a 1.194 OPS. After such a miserable time at the plate for the majority of the year, what has been the catalyst for Kiermaier's significant turnaround?

For one, he is producing his lowest strikeout rate of the year for an individual month at 19.2%, which is always an assist. While he has an extremely high GB/FB ratio of 2.11 that isn't doing his HR chances any favors, he has improved his pull rate to 41% from 29.1% in August. By far the most important, Kiermaier has currently achieved his season-best rates for hard contact and soft contact in September with figures of 38.5% and 18%. While these rates are far from elite, his improved quality of contact on batted balls combined with his speed and high frequency of line drives has netted a BABIP of .444 this month. While this has created great results on offense in general, his power still lags behind with an average HR-distance of 392-feet and a very poor exit velocity of 85.6 mph. Even at his best, his power-hitting projections should be conservative, but with more consistent play next year Kevin Kiermaier could once again be a 15-15 candidate.

Jay Bruce - (OF, NYM)

It's been a disappointing season for Jay Bruce and the New York Mets. Bruce has only gotten to take just 283 AB in 2018 and in that time he sports an OPS of .668 with just eight homers. However, he has bounced back in a big way this month with a slash of .224/.333/.510 with four dingers in 49 AB. While this year will largely be considered lost time for "Bruuuce", he has been making his best attempt to salvage the plate appearances that he has left down the home stretch of September. What aspects of his offensive approach are responsible for his power-proclivity thus far over the season's final month?

His strikeout rate for September is low for Bruce-standards at 21.1% while his 14% walk rate displays how zoned-in his plate discipline has been. Everything about his batted-ball peripherals screams "this one is out of here!". His GB/FB ratio is just 0.50 off of 48.6% fly balls and a minuscule grounder rate of 24.3%. He has produced an impressive pull rate this month of 59.5%, and his hard and soft contact rates of 40.5% and 8.1% respectively demonstrate the level at which Bruce is tuning pitches up en route to his September ISO of .286. His exit velocity (88.4 mph) and average HR-distance (392-feet) are rather pedestrian, but Jay Bruce is a notoriously streaky player who has been hampered from building momentum this season due to a series of unfortunate circumstances. However, he is doing everything right at the plate to hit for excellent power until the end of the regular season, and that means a little something extra when taken into account that the Mets are the fourth-best run-scoring offense in baseball for the month of September.

Shohei Ohtani - (DH/SP, LAA)

It's been a polarizing, phenomenal season for Shohei Ohtani as he took on the highly experimental role of SP/DH for the Los Angeles Angels. Unfortunately for baseball as a whole, it was announced that Ohtani would not be pitching in 2019, meaning his duties will be strictly offensive. Fortunately, he has been a wrecking machine at the plate over the last two months but especially September. In 46 AB this month he has already hit five HR with a belief-defying slash of .370/.463/.826 (not to mention three stolen bases). Now that we know we are looking at a full-fledged offensive player for next season, how does Ohtani's scorching September impact his stock for 2019?

This month Ohtani has been working with a high GB/FB ratio of 1.78 off of 50% grounders, and a rather standard (yet workable) pull rate of 40.6%. The big difference-maker this month has been his excellent batted-ball contact. He has been producing just 9.4% soft contact this month in conjunction with an intimidating hard contact rate of 56.3%. These factors of contact have paired together to net an ISO of .457 with a BABIP of .444 this month. With his speed (he has stolen nine bases in thirteen attempts this year) and frequency of hard contact, this ISO hardly appears to be a stark outlier and his BABIP looks sustainable at a slightly more conservative level. Shohei Ohtani is really the complete package, even if he won't be able to take the mound next season. His skill set and athleticism have put him smack dab in the middle of the AL Rookie of the Year race and his track record from Japan suggests that this type of power-hitting is well-within his long-term reach. Trust in deploying him at every chance you get for the rest of the regular season, and come next year with a full-season slate of plate appearances, Ohtani could jack 35+ balls.

Daniel Palka - (OF, CWS)

Palk-Smash! The 26-year-old Georgia Tech alum has been living up to his Marvel moniker this month with six bombs and a terrific slash of .293/.383/.732 in just 41 AB for the White Sox. We know he is capable of feats of brute strength from his 92.4 mph exit velocity and 410-foot average HR-distance, yet despite this Palka's season has been characterized by drastic ups and downs. This month, however, he has managed to roll together the right set of factors in maximizing his changes of driving a pitch yard.

His plate discipline has been dramatically better this month. After producing strikeout rates between 35.6% and 40% from June through August, Palka has finally been able to put up a far more manageable rate of 25.5% in addition to his highest walk rate of the season at 12.8%. On batted-balls, he has maintained solid figures in terms of pull rate and hard contact through most of the season and has so far kept in line with this trend with respective marks of 41.4% and 37.9%. Most poignantly, his GB/FB ratio went from 1.83 in August to 0.71 so far in September after he was able to bring his fly ball rate up by 18.3% to 48.3%. You may not be able to count on Daniel Palka for well-rounded offense or base-stealing speed, but he can be counted on to hit pitches deep...when he makes contact, which is why it is so vital for him to keep his strikeouts to a minimum moving forward. He has smacked 25 dingers in just 378 AB this season, and that kind of power is rare in such a widely available asset, so keep your eyes peeled for how he rounds out the month when considering his priority level for next season.

Power Fallers

Jed Lowrie - (2B/3B, OAK)

While his HR totals have hardly waivered throughout 34-year-old Jed Lowrie's remarkable first-time All-Star season for Oakland, he has produced a clear pattern of playing fantastic in one month and mediocre in the following. After his four dingers, .875 OPS showing in August, Lowrie has opened up September with zero homers and an unsightly slash of .180/.328/.200. A regression was likely to be expected for a player in his mid-30s in the middle of the best season of his career, but the issue becomes more perplexing when the regressions come every other month as opposed to being over the latter half of the year. To find the problem, let's first discuss what isn't the problem.

The problem isn't his plate discipline, far from it, in fact, considering he sports excellent strikeout and walk rates of 14.8% and 18% this month. The problem certainly isn't his batted-ball location. This month Lowrie has a GB/FB ratio of 0.74 off of 46.3% fly balls with an above-average pull rate of 43.9%. With all of that considered, the problem is his power and decaying quality of contact. Through the season as a whole he has managed a slightly above-average exit velocity of 89.2 mph with an underwhelming 380-foot average HR-distance, and this month he has produced season-worst hard and soft contact rates of 29.3% and 19.5%. Jed Lowrie may be coming off two consecutive career-years once 2018 is all said and done, and his place inside a top-ten batting order like Oakland's only adds to his value when he is performing up to par. His lack of raw power puts a hard ceiling on his HR totals, but even with continued streakiness in 2019, Lowrie could easily hit the 15-20 dinger range again.

Andrew Benintendi - (OF, BOS)

Much like Jed Lowrie, Andrew Benintendi's offensive peripherals seem to indicate that he is much more of a well-rounded player with an upside in speed than he is a player with strong power potential despite his consecutive six-homer months in May and June. His play has been waning slightly since the middle months of the 2018 campaign but it hasn't been a serious issue until September hit, as he has managed a goose-egg in the HR department (and SB department) with an ugly slash of .245/.255/.283 since the start of the month for the first-place Red Sox. With two bona fide power/speed seasons under his belt at the big-league level, how does Benintendi project moving forward for the rest of the regular season and 2019?

One strange thing is that he has been producing his best strikeout rate of the season (9.1%) in this poor month of September, though it has brought his walk rate down to just 1.8% when he hadn't failed to produce a rate of at least 9.7% all season. Past that, it is easy to see what offensive factors make Benintendi a great base-hitter, but not necessarily a power hitter. He has only been producing a 34.7% pull rate over the second half of the season with a 1.50 GB/FB ratio off of just 30.1% fly balls but 24.7% line drives. Most concerning though is the fact that even though he boasts a solid soft contact rate of 9.6% over the season's second half, he has only been producing 28.1% hard contact which is only down by 0.1% from the first half of the year. Andrew Benintendi is a prime candidate for a well-rounded offense as a power/speed threat with greater emphasis on stealing bases, but when he is hitting so few fly balls and making such infrequent hard contact, these kinds of extended homer-less lulls can pop up often. At least he will score plenty of runs as a member of the top-tier Red Sox batting order as long as he is a part of it.

Gleyber Torres - (SS/2B, NYY)

The Yankees offense has been clicking all season and Gleyber Torres has cemented himself as one of the top contenders for the American League Rookie of the Year award. As New York pushes towards October, Torres has produced a .269/.328/.423 slash and two homers in 52 AB for September. If you can believe it, his current OPS of .751 this month is his lowest of the year, and his slugging percentage hasn't been this low since April. So while he may be losing some ground to the likes of Miguel Andujar and Shohei Ohtani in the ROY picture, what issues of Torres's offensive results are most indicative in how to project his performance for the rest of the regular season and next year?

Torres's plate discipline in terms of strikeout and walk rate have varied throughout the course of the season but have mostly ranged from manageable to satisfactory. He also sports several factors that work in his favor towards power-hitting. His September GB/FB ratio of 0.74 comes off of 46.3% fly balls and he has also produced a 43.9% pull rate with just 12.2% soft contact. Having said that, his hard contact is less-than pedestrian at 31.7% and has resulted in a sub-par ISO of .154 by Torres's standards. This month seems to be a bit of an outlier for Torres and could easily be the result of the wear and tear from a player's first MLB season. With good contact, a lot of batted-balls can turn into bombs in Yankee Stadium, and the offense is so high-powered that any sort of production within it nets a huge bonus. Gleyber Torres is incredibly talented, and with the peripheral factors he brings to the table, you shouldn't count on him ever being kept down for too long.

Billy McKinney - (OF, TOR)

Billy McKinney has been used as an asset in several big-league trades, and he has finally landed in Toronto (for now) as a member of the Blue Jays. The former top-100 prospect got off to an optimistic start with three homers and an OPS of 1.241 in 38 August AB, but has quickly experienced growing-pains as evidenced by his lone dinger and slash of .188/.200/.271. McKinney's minor-league track record suggests that he could be a viable power/speed threat somewhere down the line, but the question is how far down the line can this be expected and what current holes exist in his offensive game that could hinder such an emergence?

His plate discipline is solid enough, he sports a strikeout rate of 24% and a walk rate of 8.3% over the months of August and September. While McKinney produced a low fly ball rate of 34.4% over the last two months, he also only produced 37.5% grounders, leaving a 28.1% gap for line drives. His pull rate of 45.3% has been very helpful since the start of August, and even though his hard contact rate is low over that same time period at 34.4%, he has kept the soft contact at a near minimum at 9.4%. His hard contact rate for his work in August was fantastic at 55.2%, but has since dropped all the way down to 17.1% during his misery of September, while his soft contact rate only went from 6.9% to 11.4%. Billy McKinney has already proven capable of finding big-league success at the plate, and his offensive peripherals suggest that he possesses many of the skills required to continue finding success next season. His struggles for September may likely be associated with the fact that he has had such limited MLB experience, but if he receives the playing time this guy could certainly go for 25 HR and 10+ stolen bases next year.