Major league baseball is so deep in quality starting pitching that you could probably make the case for nine or 10 different combinations as the best pair going right now. Here are my top five:
This may surprise you, but Hernandez and Iwakuma have the highest WAR (wins above replacement) of any pair of pitchers in the majors. And before we write off Iwakuma's outstanding start to the season as a fluke, here are the American League ERA leaders going back to last July 1, when Iwakuma joined the Mariners' rotation:
Justin Verlander: 2.77
James Shields: 2.86
Hiroki Kuroda: 2.97
So the M's have Hernandez, one of the best pitchers in baseball, a guy who has pitched 230-plus innings the past four seasons and who has been as effective as any starter in the game for nearly a year. And they have Iwakuma, who will give up some home runs, but he's walked only 11 batters in 10 starts and his splitter has turned into a wipeout pitch -- batters are hitting .184 off it with one home run, 35 strikeouts and two walks in 79 plate appearances ending with the pitch. If the Mariners fall out of the wild-card race, maybe they'll look to trade Iwakuma while his stock is high, but I fear that would be a mistake and they would be making a Doug Fister-like trade that backfires. Iwakuma is for real.
2. Justin Verlander and Anibal Sanchez, Tigers
The Tigers' rotation is so good that you could also slot Fister or Max Scherzer here and have an equally terrific duo. I still like Scherzer as the club's No. 2 as the season progresses, but Sanchez has been terrific so far and has ramped up his strikeout rate to new highs, up more than 9 percent from last season (68 in 55.1 innings). His ERA is 2.77, and while his home run rate is probably unsustainable (just two allowed), his BABIP is too high on the other end at .356. Moving forward, those two results should cancel each other out as they normalize and Sanchez should remain outstanding.
Kershaw is the best pitcher in the game right now -- he's gone 22 consecutive starts allowing three earned runs or fewer, the longest such streak since Pedro Martinez had 23 in 1999-2000 -- and Greinke would be the ace of many teams. Now that Greinke is back from his broken collarbone, we'll see if everyone has written off the Dodgers too quickly.
4. CC Sabathia and Hiroki Kuroda, Yankees
Somehow, Kuroda still flies under the radar despite playing in New York. He's not flashy, but batters are hitting .201 AVG/.254 OBP/.292 SLG against him. There's some luck going on here since his .229 BABIP will probably rise, but his slider has been untouchable: opponents are 8-for-61 (.131) against it without an extra-base hit. Meanwhile, Sabathia has lost some velocity off his fastball, but he pitches down in the zone more, throws strikes and keeps the Yankees in games. Since his pitch counts have run high at times he's averaging only 6.5 innings per start, so maybe his days as a 230-inning workhorse are over (he missed a few starts last year, remember, and pitched just 200 innings). Remember as well that these guys have to pitch half their games at Yankee Stadium, where routine fly balls can land in the right-field stands.
Yes, young guns Shelby Miller and Matt Harvey have seemingly pushed Strasburg out of the limelight, but he's still pretty good and still throws hard (best average fastball velocity among starting pitchers). Nonetheless, he's been surpassed by Zimmermann as the club's ace. Zimmerman doesn't rack up the huge strikeout totals so the advanced metrics like FIP and xFIP suggest his ERA will rise (well, it will, since it's at 1.62 right now). But he throws strikes with Maddux-like precision (nine walks in nine starts) and while there were concerns heading into the season about his ability to go deep into games, his efficiency has allowed him to toss three complete games without throwing more than 107 pitches. He's 7-2 and could be 9-0 -- in the two games he lost, he allowed two runs.
That's my top five, and I couldn't find room for Adam Wainwright and Miller, Clay Buchholz and Jon Lester, Cliff Lee and Cole Hamels, Chris Sale and Jake Peavy, Matt Moore and David Price, Matt Harvey and anybody. It's a pitcher's game right now, that's for sure.