MLB's top 10 defenses: Royals edge D-backs for top spot

Alex Gordon (left), Jarrod Dyson (center) and Lorenzo Cain bolster the league's top-ranked defense. Jamie Squire/Getty Images

This is Part VI of our series ranking the best team units. Today we focus on the best defenses, according to club evaluators -- and out of all the various units we've ranked, picking the best defensive group proved the most difficult.

The Kansas City Royals have played in the World Series the past two years in no small part because of how exceptional they are on defense, and they are an example of the way the entire sport is trending. This winter, teams are spending more on defense (hello, Jason Heyward) and veering away from sluggers who are defensively challenged (like Chris Carter and Pedro Alvarez), and the Royals are the best current example of the idea that success can come through fielding a bunch of guys who make plays on defense.

On the other hand, defensive metrics suggest that in 2015, the Arizona Diamondbacks were MLB's best glovemen -- and according to the defensive runs saved (DRS) statistic, it wasn't even close.

Team leaders in defensive runs saved, 2015

1. Arizona Diamondbacks 71 DRS

2. Kansas City Royals 56

3. Miami Marlins 37

4. Houston Astros 30

5. San Francisco Giants 28

So which group should be No. 1? Presenting the top 10 defenses in MLB:

1. Kansas City Royals

Look, both Arizona and Kansas City are worthy of the No. 1 spot, and compelling arguments can be made for both. A couple of developments swung the top spot to the Royals, though. First of all, Kansas City was able to retain four-time Gold Glove-winning left fielder Alex Gordon with a four-year deal. Gordon is not as dominant defensively as he was a few years ago, when he was a shutdown corner outfielder in the way that Heyward is now, but he's still very good out there, still makes plays, still works relentlessly. It also appears that the speedy Jarrod Dyson is poised to get more playing time in the outfield than he has in recent seasons, and since he'll be alongside Gordon and Lorenzo Cain, a whole lot of balls driven into the gaps against K.C. will be run down. It's a good time to be a Kansas City pitcher.

Additionally, the Diamondbacks traded the versatile Ender Inciarte, a strong defender who was fourth in DRS among left fielders with 300-plus innings there in 2015 and second (behind Heyward) among right fielders, as part of the Shelby Miller deal, and now Yasmany Tomas figures to get the bulk of the playing time in right field, with David Peralta in left. The Diamondbacks believe that Tomas' defense is better than it's generally thought to be and will improve as he gets more experience, but he posted a minus-8 DRS in about 500 innings of outfield time last season.

The Royals' infield defense is excellent as well, with three-time Gold Glove winner Eric Hosmer at first base, Gold Glover Alcides Escobar holding down shortstop and Gold Glove candidate Mike Moustakas at third. Omar Infante and Christian Colon could split time at second base.

Catcher Salvador Perez also has won three Gold Gloves, and while rival evaluators see little things in his defensive play that they'd love to see him clean up, he's greatly respected for his on-field presence and the way he works with pitchers.

2. Arizona Diamondbacks

Center fielder A.J. Pollock led NL center fielders in DRS in 2015, and first baseman Paul Goldschmidt won his second Gold Glove for his defensive play. Shortstop Nick Ahmed is like the Kevin Kiermaier of infielders -- casual fans aren't necessarily familiar with him, but scouts are, having seen him make a lot of athletic plays like this one.

The overall standing of the Diamondbacks' defense could swing on the choice the team makes at second base. Chris Owings could be the second baseman, giving the Diamondbacks a dominant defensive infield, or Arizona could look for more run production from the spot and opt for Aaron Hill's power. Catcher Welington Castillo joined the Diamondbacks last June, and Arizona really liked his work with the pitching staff.