Series preview: Kansas City Royals' defense is so good their weaknesses are mostly irrelevant

On Monday night, the Pirates will begin a road series against the Royals, sending A.J. Burnett, Gerrit Cole and Charlie Morton to the hill. Here's what to expect from Kansas City. I'm going to organize this preview a little differently than I have previously, because the Royals are a different sort of team. They're also great. The rare Pirates/Royals series used to be a giant joke, but now both teams are among the best anywhere. What a world.

RUN PREVENTION: 3.50 ERA, 3.83 FIP, 4.14 xFIP. 7.1 fWAR, ninth in the American League. The Royals reputedly have a terrific bullpen and a terrible starting rotation. It might be more accurate to say that neither of them are that great, but that their defense is so brilliant that it doesn't matter.

The Royals do have a 2.17 ERA out of the bullpen, but advanced metrics like xFIP and SIERA suggest they're only a bit better than league average. Wade Davis is a monster, but the rest of the bullpen actually isn't particularly strong. Greg Holland's velocity has dropped this season, and his ERA has swollen as a result; Kelvin Herrera has never posted peripheral numbers worthy of his stuff, or of his connection with Davis and Holland; Ryan Madson and Franklin Morales are good reclamation projects but no one to fear; and so on.

The Royals' rotation, meanwhile, is outright bad. If you believe the peripherals rather than the results, their best starter has been Yordano Ventura, who starts against the Bucs Monday. Ventura has a 4.73 ERA, but that seems to be mostly because he's one of a few guys not benefiting from the Royals' defense. He isn't throwing as hard as he did last season, but, at least in theory, he's mostly made up for that by inducing a few more ground balls. Tuesday's starter, Jason Vargas, is making his first big-league start in more than a month after missing time with a flexor strain. He's a soft-tossing lefty who limits walks. The Royals haven't named Wednesday's starter and are sorting through a variety of rotation options. In any case, they've blunted the impact of their weak rotation by simply having their starters pitch fewer innings than they otherwise might -- their starters' total of 501 innings pitched ranks second to last in the majors.

Also, there's the Royals' defense, which is otherworldly. You could put a rotation of five John Van Benschotens in front of these guys, and it would be watchable. As a team, the Royals are 42.1 runs above average on defense, according to FanGraphs. The next best team is the Rays, who are a full 17 runs worse. The Royals are just behind the Rays at the top of Baseball Prospectus' Defensive Efficiency chart.

Here's a complete list of current Royals who are bad at defense: Kendrys Morales. That's it. And he mostly plays DH. Don't hit the ball to their outfield -- Lorenzo Cain and Jarrod Dyson will catch it, and so will rookie Paulo Orlando if he gets the chance. (Another excellent defensive outfielder, Alex Gordon, is currently on the DL.) Don't hit it to their infield -- Alcides Escobar is one of the game's best defensive shortstops, and Eric Hosmer, Omar Infante and Mike Moustakas are solid as well. Don't do anything that involves the catcher -- Salvador Perez is a beast. Don't. Don't. Don't. Don't. Don't. (Also, if you are thinking of clicking that link while you're at work, don't.)

OFFENSE: .274/.324/.409. 17.4 fWAR, first in the American League. That very high WAR is, of course, mostly due to the defense, but even without Gordon, the Royals are a solid hitting team. Cain, who's batting a remarkable .321/.378/.513 (and .429/.500/.753 over the past month), has quietly developed into a star, and Hosmer, Morales, Moustakas, Dyson and Escobar have all been solid contributors. Infante, Perez and Alex Rios haven't hit well this season, however.

OVERVIEW: That I got the James Shields trade wrong has been amply discussed here. The Royals made the World Series last season and energized their fan base, and Wil Myers has had trouble staying healthy. The trade has gone swimmingly for the Royals, and it continues to, with Davis still performing well in Kansas City.

I still think it was an odd trade, though. Now Shields is gone, and this year's team is getting strong contributions from guys like Cain, Hosmer, Moustakas and Dyson, who were all in the early stages of their careers when the trade took place. This year's team is markedly better than last year's, and having someone like Jake Odorizzi, a cost-controlled and good young pitcher who the Royals shipped out in the Shields trade, really would have helped their foundering rotation. The Shields trade was controversial because it cut against the sabermetric wisdom that you only make big going-for-it trades when you're ready to contend right away. It looked like the Royals were jumping the gun, and I still think they were, and yet it worked for them.

History shows, however, that such trades are extremely risky even when you're ready. For example, the Shields deal might not even be the trade most crucial to the Royals' recent period of contention. The Royals only had Odorizzi in the first place because they acquired him from the Brewers when they traded Zack Greinke in 2010. When you trade someone like Greinke, you've got to get a lot in return, and the Royals absolutely did, landing not only Odorizzi but also Cain and Escobar. That's just an insane haul, and it's probably the single biggest reason the Royals are in first place and the Brewers are in last.

What does all this mean? I'm not sure, except that the Royals have gotten great results in key trades. They've also had a bunch of high draft picks like Gordon, Hosmer and Moustakas who have provided them with a cheap and effective foundation. That combination is likely to result in lots of wins. If Dayton Moore can pull a good starting pitcher out of his hat at the trade deadline, that would help, but he might not even need to -- the Royals can ill afford to be on the wrong end of one of those Greinke-type trades, and their defense gives them a very high floor almost regardless of who their pitchers are. Despite their well publicized rotation troubles, they're actually first in the AL in runs allowed. Extra starter or not, the Royals are well positioned for another playoff run.