The Cincinnati Reds have an ace in the making in Luis Castillo

Luis Castillo wrapped his rookie season in style on Wednesday, firing 8 innings of 1 ER ball against the Milwaukee Brewers, striking out 10, walking none, and yielding just 4 hits in the process. A dominant outing, to be sure, and one that both he and fans alike won’t forget anytime soon.

What’s funny, though, is that it wasn’t even his best outing of the season, at least not according to FanGraphs’ Game Score - that came in his outing against the Miami Marlins, the team that traded him to the Cincinnati Reds last offseason as the centerpiece of the Dan Straily deal. Rest assured, this isn’t an article meant to unwind the excitement surrounding his display on Wednesday; rather, it’s an exercise in highlighting just how damn good Castillo’s remarkable rookie season was.

In fact, let’s look closer at how he stacks up against his peers.

• A mix of 29 rookie pitchers - some relievers, some starters - have thrown at least 60 IP so far in 2017. None has a better ERA than Castillo, who sits atop that list at 3.12.
• Rest assured, that ERA hasn’t been the result of fluke plays or based purely on the fact that the Cincinnati defense is stout, either. His 3.72 FIP also ranks as the best of that bunch.
• We’ve marveled before at exactly how hard Castillo throws the ball, especially given how easy his delivery appears while you drool at the radar gun reading. Well, among all rookies in the game who’ve thrown at least 10 IP this year - 65 of them, to be exact - Castillo’s 97.5 average fastball velocity was the best of them all.
• Not to be outdone, among all MLB starters - not just rookies - who’ve thrown at least 30 innings during the 2017 season, Castillo’s 97.5 mph average fastball velocity sits tied with Yankees starter Luis Severino for the best in all of baseball. That’s out of 206 different pitchers, no less.
• Perhaps a stat in which he doesn’t rank as the absolute best in the game is one that might well stand out as the most important in the long run, however. Out of that same 206 starter sample that has thrown at least 30 innings this season, Houston Astros ace Dallas Keuchel and his 66.9% ground ball rate rank as the best in all of baseball. However, you don’t have to go far down the rankings to find Castillo’s name, as his 58.8% mark checks in as the sixth best on that list. With GABP as his home ballpark for at least the next five years, how vital the ability to regularly induce ground balls is cannot be understated.

***********

To say that Luis Castillo was an afterthought coming into this season would be a bit too strong, but not wholly inaccurate. The likes of Cody Reed, Robert Stephenson, and Amir Garrett were supposed to be the rookies we watched emerge this season, as they stood high on the totem pole and had plied their trade at the AAA level within the Cincinnati system in front of our watchful eyes already. Castillo, meanwhile, had only tossed 14 innings above A-ball in his professional career, and had done so as a member of the Marlins organization.

And, of course, he’d only come to the Marlins after having been traded there by the San Francisco Giants for Casey McGehee, and the Marlins had even shipped him to San Diego for a minute before the Colin Rea elbow kerfluffle saw him returned to Miami. Pair that history of being deemed expendable with a lack of any Top 100 prospect list love, and it was easy to dismiss his chances of impacting the 2017 Reds.

In hindsight, though, it can’t be emphasized enough how much the Cincinnati front office and GM Dick Williams deserve a high five for landing Castillo, as trading Straily, his league-minimum 2017 salary, and three additional years of team control initially looked a bit brash given where Cincinnati’s pitching staff has stood of late. Placing Castillo as the centerpiece of such a deal took both confidence and conviction in his ability to not just replicate Straily’s success from 2016, but to show the kind of dominant capability to lead a staff that needed a top-tier talent like his.

If 2017 is just the tip of the iceberg, what Castillo has left in store is exactly what rebuilding clubs should be excited about. Hell, it’s what any club at any state should be excited about. And while Cody Bellinger and his crazy dinger total is going to win the National League Rookie of the Year this year, rest assured that you shouldn’t consider yourself crazy for saying you’d rather have this Cincinnati rookie over the long term instead.