Luis Castillo's 2017 debut was fantastic as he displayed the ability to get whiffs while also generating a pristine batted-ball profile. That makes our heart go pitter-patter.

But in 2018, Castillo hasn't lived up to the lofty expectations the fantasy community had for him when they drafted him as a top-30 starting pitcher, per NFBC's average draft position (ADP) data. ESPN's Player Rater has Castillo 140th among starters, and his numbers have dipped -- some in a big way -- across the board, with the Cincinnati Reds' righty losing his eye-catching batted-ball marks.

Castillo has underwhelmed -- there's no arguing that -- and the spike in hard-hit rate coupled with the steep drop in ground-ball rate is troublesome. Lefties have killed him as he's surrendered a .384 wOBA, 44.7% hard-hit rate and 39.6% fly-ball rate in the split.

But strikeouts can mask a lot. Castillo's 21.5% strikeout rate is a touch below the league average (22.3%), but his sky-high swinging-strike rate hints at some positive regression in the strikeout department. Castillo had a much better strikeout rate a year ago despite a markedly worse swinging-strike rate.

Among qualified pitchers, Castillo's swinging-strike rate checks in sixth, but his strikeout rate pales in comparison to that of the other leaders in swinging-strike rate.

Castillo is going to be prone to the occasional blowup outing -- especially at home -- if his hard-hit rate stays where it is. However, he should produce more punchouts going forward if he can maintain this kind of swinging-strike rate, and that's enough to make him a worthwhile buy-low dart throw.