Even though I was tempted last week, I decided to put off talking about the Astros' rotation. Since then, they've gone 6-2, with both of their losses coming in one-run games. In those eight games, the rotation has pitched 51 innings and notched a 1.76 ERA. The icing on the cake came in their last game on Wednesday, when Justin Verlander pitched a complete-game, five-hit shutout against Mike Trout, Shohei Ohtani and the rest of the Angels, in which he accumulated his 2,500th career strikeout. The gravitational pull has gotten far too strong (space/Astro-logical pun intended), and it's time to ruminate on the rotation down in Houston.
When the Astros won the World Series last year, they did so largely on the strength of their MLB-best offense. It wasn't just the best offense in baseball last year, it was one of the better offenses of all time. Since the Astrodome opened its doors in 1965, only the 1976 Reds (they of the "Big Red Machine" moniker) possess a better team-wide, non-pitcher wRC+ (130). The 2017 Astros are tied for second place with a 122 wRC+.
Their pitching was certainly good enough, as it must be, to win the World Series. But it wasn't quite as unstoppable as the lineup, with the rotation coming in 6th in fWAR, ERA and FIP. Those numbers, of course, include the trade deadline (literally) addition of Justin Verlander, who they are now enjoying for a full season's duration.
Given the strength of their offense in 2017, and the previous addition of Verlander, they might have stood pat over the offseason, as reigning champs are wont to do. But, nope, they went and snatched up Gerrit Cole from the Pirates. It seemed like Houston was accumulating an embarrassment of riches, adding Cole to a rotation that, already looked to be one of the best in the league. The early returns are in, and that presumption was correct, as Houston's starters have been embarrassing hitters all season.
The aforementioned Verlander and Cole have combined with fellow starters Lance McCullers, Charlie Morton and Dallas Keuchel to post a 2.24 ERA (1st in MLB) and 2.90 FIP (1st) with excellent peripherals, 10.65 K/9 (1st), 2.52 BB/9 (3rd) and 0.81 HR/9 (2nd). Unsurprisingly, then, they also are atop the fWAR leaderboard with 8.4, and it's not even close, as the second-place Nationals rotation has only accumulated 6.0 fWAR.
Verlander is leading the charge with gaudy numbers that are even better than his Cy Young and MVP-winning 2011. His 1.05 ERA leads all of MLB, while his 2.20 FIP comes in 4th. His 11.01 K/9 is "only" good enough to spot him 9th place, but his 1.83 BB/9 comes in 14th in MLB and is better than the eight starters who are notching up more strikeouts than he is. He has a 376 ERA+ on the season, which, I can't even. For reference: Pedro Martinez put up a 291 ERA+ in 2000 and Greg Maddux put up a 271 ERA+ season in 1994.
Those numbers are ridiculously ridiculous, but the season is still young (obviously) and he also has a ridiculous .205 BABIP (vs. .284 for his career) to go along with them. His home run-to-flyball ratio is also an extremely low 4.6% (versus 8.2% for his career). Both of these stats suggest that he's gotten lucky when it comes to balls finding gloves and staying in the park (although it's worth pointing out that Verlander, with 256 batters faced, is over halfway to the 400-batter threshold which would allow us to start to trust the HR/FB% improvement).
But, even with some small-sample-size-based luck, it's not as if we're talking about a complete mirage here. Those peripheral stats we already touched on back that up, as does his career-best 13.4% swinging strike rate. Oh, and, Verlander has basically been this good going back to when he arrived in Houston last year, so we're actually dealing with a larger sample size here that suggests that he might even be back on a Hall of Fame trajectory.
Regardless of Verlander's future over the length of his contract and career, he's already put up 2.7 fWAR through his 10 starts in 2018, and he can't even claim sole possession of first place thanks to one of his teammates. Like Verlander, Cole is putting up the best numbers of his career. He has a 1.75 ERA and 1.96 FIP (4th and 2nd in MLB respectively) and outstanding peripheral stats, with a career high 13.96 K/9 (which is 2nd-best among qualified starters), 2.04 BB/9 and 0.73 HR/9. The last of those stats was a serious problem for Cole last year, when he have up 1.37 dingers every nine innings, which was the 15th worst rate among qualified starters.
Cole has been throwing less fastballs (55.4% versus 64.1% for his career) and has dramatically increased his curveball usage (18.4% versus 12.0% for his career). A change of scenery to Houston has certainly done Cole a world of good. Whether or not you want to buy into Trevor Bauer's claim that Houston pitchers are using foreign substances to increase their spin rate is a story for another day, and one that probably requires a bit more in the way of proof and I'm not ready to go down that road just yet.
The Astros may have the best two pitchers in baseball by fWAR, but it's not as if the rest of the rotation has failed to deliver. McCullers has 1.2 (17th in MLB), Morton has 1.0 (28th) and Keuchel, their "least valuable" starter, with 0.7 fWAR, is still tied for 42nd place in MLB by fWAR out of a field of 94. When your "worst" starter is still in the 50th percentile (and tied in fWAR with Clayton Kershaw, no less), things are probably going pretty good.
The moves in the rotation caused further dominos to fall, as well, pushing Brad Peacock and Colin McHugh into the bullpen. While Joe Smith has been struggling, Hector Rondon has been excellent, and the bullpen as a whole has put up 2.1 fWAR and is 4th in MLB (compared to 8th last season). Although, in yet another unsurprising development, Astros starters lead MLB in innings pitched (289) and it's not as if the bullpen is getting much work, relatively speaking. It might be surprising that the bullpen has even been as valuable as it has been, given how little they've pitched (113 innings, 29th in MLB).
All those good things having been said, it's unlikely that the rotation will make it through the year with a clean bill of health, if only because a supremely healthy rotation is a rare, beautiful butterfly in this day and age. The 2016 Cubs were the exception, rather than the rule. Morton has a track record of hitting the DL on an annual basis going back 2012, for one. But then you remember that the Astros have Peacock and McHugh as options if and when that happens. When you push ostensible starters into relief roles, you can call on them when you need them.
We also mentioned some aberrations (BABIP, HR/FB%) when discussing Verlander. The rotation as a whole has the best BABIP in MLB (.250) and, while the Astros have been good (but not amazing) by most statistics (collectively they are 13th in MLB by UZR and 8th by DRS), it's not as if they've got a team full of Andrelton Simmonses running around and stealing hits all over the place. They've also collectively got a 83.2 left-on-base percentage that is far and away the best in baseball. It would be wise to expect some regression in one area or another going forward.
But in the event that rotation does eventually take a step back (or someone hits the shelf for a bit), we have to consider that the offense has been woefully underperforming expectations as well. We're not going to dig too deep into that right now, as that's yet another subject for another day, but it suffices to say that there's every reason to believe that things should improve on the offensive side of the ball.
The Astros' rotation almost certainly won't be this good all year long, but it's worth admiring just how good they've been to this point, because they are historically good right now, just as their offense was last year. The aggressive moves to improve the rotation made by GM Jeff Luhnow are certainly paying huge dividends. It's rare that we see teams that were as good as the Astros were last year go out and get even better. We haven't seen a repeat World Series winner yet this century and, while the Astros are a long, long way from that happening, that doesn't mean we shouldn't appreciate just how great Houston's rotation has been so far.