Every year, there are a handful of players who seemingly come out of nowhere to put up great numbers and force their way into fantasy relevance. Be they former prospects who have never impressed, unheralded young call-ups, or bench pieces who finally get a shot at a starting gig, these guys generally go undrafted or unrostered to start a season before becoming integral parts of contending fantasy teams. They also tend be over-drafted and/or highly sought after in the trade market by owners who missed out the previous year. Sometimes, those owners get caught up in the frustration of missing the ‘next big thing’ and fail to look past the flashy numbers and ask: “was it real?” One of the players who perfectly fits this archetype is the Reds surprising 2016 slugger Adam Duvall.

A 2010 draftee of the San Francisco Giants, Duvall posted excellent power numbers throughout his minor-league career. He finally got the call in 2014 and saw 77 plate appearances coming off the Giants bench. However, the power he previously showed failed to make the jump with him and poor plate discipline coupled with a low BABIP earned him an underwhelming .192 batting average. He spent most of 2015 in AAA, and a month after being traded to the Reds he made his Cincinnati debut. Duvall’s second MLB stint wasn’t anything special either, but with a .266 ISO he at least showed he could hit for power in the big leagues. When finally given a starting role to begin 2016, the 27-year-old delivered in a big way by socking 33 home runs, driving in 103 RBI, and posting a .241/.297/.498 line, complete with a massive .257 ISO.

While some of those overall numbers definitely look enticing, a deeper look reveals some troubling underlying trends. Foremost, those numbers were buoyed by an incredible 32 game stretch from May 3^rd through June 7^th in which he hit 15 home runs and put up an astounding .444 ISO and 175 wRC+. That is nearly half of his full season home run output in just over a month. Over the other 118 games, Duvall hit a paltry .223 with a .205 ISO. According to just about every advanced metric, he was well below average.

A glance at Duvall’s heat map data provided by Fangraphs shows one reason for both the surge and massive decline. Throughout that month-long hot streak, 13.1% of the breaking balls Duvall saw were right down the middle, more than any other location. He took advantage of it by slugging .941 on them at a contact rate of 92%. However, for the remainder of the season opposing pitchers began taking him out of the zone low and away at an increasing rate. From June 8^th on, the vast majority of breaking balls Duvall saw fell into this category and he took the bait swinging at 42% of them with a 43% contact rate and putrid .192 slugging percentage. This trend also contributed to a 27% strikeout rate, continuing his trend of elevated MLB K-rates. All of this brings into focus the fact that as the season wore on, the book got out on Duvall and pitchers adjusted. If this continues into 2017, the picture is that of slugger with plenty of power but very little opportunity to tap into it. The chances of another season-saving hot streak are pretty slim.

Currently, Duvall’s ADP is that of a top-40 outfielder, and he is going ahead of guys like Kole Calhoun, Joc Pederson, and Marcell Ozuna. He was the 27^th outfielder taken in our recent (and still on-going) TDG99 draft. But for the majority of last season, he was nearly unrosterable as his mediocre power output did not make up for the extreme drain in the average department. Pederson has a similar high strikeout/low average profile but walks twice as much. He also has age and development time on his side, along with potentially some speed. Calhoun gets overlooked due his lack of gaudy stats, but he has been a consistently above average hitter throughout his career. The 26-year-old Ozuna has also proven to be a solid hitter when healthy, providing decent average and power. With Duvall’s expected power regression, I expect all three to provide similar home run output without killing you in other categories. Of course, there is plenty of power in his bat. But unless he figures out how to change his approach, it may be a moot point.

Duvall’s current value represents the dangers of viewing season-long stats as a whole without delving deeper. If you are drafting a new dynasty team, don’t fall into that trap. If you already own him, now may be the best time to sell. Take advantage of other owners who may be blinded by the “30+ Home Run Potential” and are willing to gamble on another world-beating month. In dynasty leagues, that could be a big risk to take on a guy without a long track record of success entering his age 28 season. Especially when there are better options at a similar price.