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HERE'S A RIDDLE: How have the Royals crushed the AL (and, uh, "dominated" the All-Star voting) with an average offense and a just-better-than-mediocre rotation? Simple: Kansas City has baseball's best defense, leading the league in defensive runs saved (DRS), which quantifies how many runs each defender saves or allows compared with his position average. So who contributes to this elite unit? And how much can defense actually impact the standings? Let's take a spectacular dive inside the numbers.

D is for definitive

The Royals' D isn't just great. It isn't just far and away the best in baseball this season. It is on pace to be among the greatest in history. The team's ultimate zone rating, which measures how much ground each defender can cover, is 37 runs better than average, more than 40 percent higher than that of the second-place Rays. Meanwhile, DRS says KC's defense has prevented 39 more runs than the average team's. Project that over 162 games and the ZiPS system says the Royals will save 95 runs this season, enough to rank as tied for the eleventh-best defensive team ever. Among the first 11: four World Series teams and three others that won 116, 98 and 97 games.

D is for deep

A good defensive team might have two Gold Glove candidates. The Royals have them at nearly every position. Seven of the eight starting defensive players have been above average with the leather in 2015. Leading the team is CF Lorenzo Cain, who has saved nine runs himself this season, fourth best in baseball. Next to Cain is rifle-armed Alex Gordon, who, after winning a Gold Glove last year and amassing 27 DRS, has saved four runs in 2015 and is nine runs better than average in UZR, which ranks first among all LFs. In front of those two? An elite defensive infield, from 3B Mike Moustakas (6 DRS) and 2B Omar Infante (5) to 2014 Gold Glove winners Salvador Perez (5) and Eric Hosmer (3) at catcher and first base. Royals fans fell short in voting their entire starting lineup to the All-Star Game, but with four starters, if the AL loses, it won't be due to a lack of defense.

D is for decisive

It took one start in front of the Royals' defense for new rotation anchor Edinson Volquez to declare it the league's best. The rest of the staff owes the D a huge hat tip too: If you gave Kansas City a league-average defense instead of its assortment of world-beaters, the team's ERA would swell from 3.52, third in the AL, to 3.99, which would rank ninth. And as for the standings? Zero out the Royals' 39 defensive runs saved and it would translate to four fewer wins. Now give them the leaky gloves of the Philadelphia Phillies, the league's worst defensive team (minus-74 runs saved) and the Royals, on pace to win 94 games, would win 71.

All stats through July 6.