It happens every year: A bunch of players produce way above expectations, and we spend the entire offseason arguing over whether or not the improvement was genuine. Separating the wheat from the chaff when it comes to last year’s breakout performances can be the difference between a championship season and bitter, abject failure for your fantasy team. After all, if you ain't first, you're last.

Throughout the rest of this month, I’ll be taking a look at some of last season’s surprises, be they breakout or bust, and offering my thoughts on each player’s fantasy outlook for 2017. We’ll kick things off with three players ready to be read their rights by the regression police.

Editor's note: Be sure to also check out our 2017 fantasy baseball rankings dashboard. It's already loaded up with tons of great rankings articles and draft analysis. Aside from our tiered staff rankings for every position, we also go deep on MLB prospect rankings, impact rookies for 2017, and dynasty/keeper rankings as well. Bookmark the page, and win your drafts.

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2017 Regression Candidates

Brian Dozier, Minnesota Twins

Dozier was nearly a Dodger, but the Twins held out for more than Jose De Leon and L.A. called their bluff. He struggled early last season before playing out of his mind in the second half. He wound up finishing the season with 42 home runs, nearly as many as he’d hit in the previous two seasons combined. Dozier also hit .268, easily a career best.

There is evidence of a change in approach here. Dozier, as he has every season of his MLB career, increased his fly ball rate. Unfortunately, his infield fly rates also increased every year – until 2016, when he cut them to a career low. Dozier also added several points to his hard contact rate. Still, a repeat seems unlikely. Owners would do well to recall the floor we saw from Dozier and not simply the ceiling. Through the end of May, Dozier was hitting .202/.294/.329 with five homers and three steals. A lot of owners probably dropped him and lived to regret it.

Dozier’s still a good bet for 25-30 homers, 15-20 steals, and 100 runs, but his current ADP (34) seems a bit rich.

Jean Segura, Seattle Mariners

I was extremely slow to come around on Segura’s reemergence last year. To be fair, he’d been one of the worst hitters in baseball for the previous two and a half seasons, so some skepticism was warranted. Segura wound up a legitimate four-cat stud, hitting .319 with 20 homers, 102 runs, and 33 stolen bases. I still would’ve expected some pullback, but there wasn’t anything egregiously fluky about his performance.

Then he got traded to the Mariners, and a chunk of his potential value evaporated. It wouldn’t be accurate to say that Segura was a product of Chase Field, but he did hit better there than anywhere else. The Mariners’ lineup should be pretty damn good and Segura will slot into the two-hole, so 100 runs could happen again. It’s worth noting, though, that the M’s stole only 23 more bases than Segura as a team. With him and Jarrod Dyson atop the lineup, Seattle certainly have the personnel to run more this year. It remains to be seen if they will. The specter of fewer opportunities, plus the likely steps down in average and power, are enough to make me balk at Segura being a borderline top 50 player (ADP: 53).

Aaron Sanchez, Toronto Blue Jays

As a rookie in 2014 and 2015, Sanchez pitched well out of the bullpen, but his performance as a starter left much to be desired. In 11 starts, he threw 66 innings with only 42 strikeouts and 37 walks. So how did he go from that lackluster showing to posting the best ERA in the American League last season?

The most critical improvement Sanchez made was getting ahead of hitters more often. His F-Strike% increased by over seven points, although this still only put him in the middle of the pack among qualified starters. While Sanchez continued to make his living primarily with his fastball, he showed greater consistency with his secondary offerings. Only his little-used slider was a negative according to PITCHf/x values.

ERA estimators still don’t love Sanchez. A glance at his BABIP marks to this point in his career would suggest he has some suppression ability, but Statcast data doesn’t really support that assertion. His exit velocity metrics were nothing special, and groundball-heavy pitchers don’t tend to consistently post low BABIPs, since groundballs are more likely to go for hits than fly balls. He is only 24, however, and we’ve already seen him make adjustments. Another leap forward could well be in the cards – just don’t pay an expectant price.

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