DENVER -- Matt Chapman was amazed when he watched the flight of baseballs during batting practice at Coors Field prior to Friday night's series opener between the A's and Rockies.
"Wow, the ball flies here," he said as he watched from the visiting dugout.
As the Athletics' third baseman stepped onto the field in Denver -- the same day he stepped on Colorado soil for the first time in his life -- it was the first time he took the same field in the same game as Rockies superstar third baseman Nolan Arenado since the two were teammates at El Toro High School in Lake Forest, Calif.
Now considered the best defensive third basemen in their respective leagues, both played shortstop at El Toro, with Arenado the starter and Chapman his understudy. Neither knew just how far they'd come within the next few years, and their paths finally crossed as Major Leaguers on Friday.
"Our high school coach [Mike Gonzales] is probably really happy," Arenado said, smiling. "[Chapman] was my backup shortstop, and when I pitched, he played short. So it's kinda funny.
"He's probably way better than me now."
Arenado was certainly being modest there. As the only third baseman in MLB history to win Gold Glove Awards in each of his first five seasons, and now a perennial National League Most Valuable Player candidate, Arenado has ascended to superstar status. And he's only getting better, entering play Friday with the highest OPS+ of his career (142) and a 4.1 WAR (per Fangraphs), which ranked second in the NL. Defensively, he has been peerless with his jaw-dropping plays at the hot corner.
But Chapman is not only rising. He's rising fast. In terms of Defensive Runs Saved, Chapman entered Friday leading all Major League players with 23, far outpacing the two players tied for second at 17 -- the Brewers' Lorenzo Cain and the Royals' Alex Gordon. As far as third basemen go, Chapman's 23 defensive runs saved were 14 runs better than Jose Ramirez's second-ranked nine.

Arenado, somewhat surprisingly, entered Friday's contest with three Defensive Runs Saved, tied for fifth among MLB third basemen. But don't let that fool you. A three-to-four-month sample in a single season is too small to draw conclusions from in terms of DRS. In fact, a full season can even be challenging to glean much from, as defensive metrics can swing substantially from year to year.
DRS is used to measure a player's range, positioning and first step, areas in which Arenado has been among the game's elite throughout his career. Where baseballs are hit and how far a player needs to go to make certain plays can certainly affect his DRS over a relatively small sample.
Chapman has been spectacular, making highlight-reel plays on a regular basis that rival Arenado's, which have become customary over the years. Chapman, by contrast, was drafted out of college (Cal State Fullerton) and is in his second Major League season, whereas Arenado turned pro out of high school.
There have been occasions during which Chapman has made plays that looked eerily reminiscent of Arenado's, leading to the obvious question: "Is there something in the water out in Lake Forest, Calif.?
"There's nothing, man," Arenado said, laughing. "It's the same water."
Chapman, being two years younger in age and Arenado's backup, said he has probably been influenced by Arenado's work ethic and style of play -- particularly defensively -- more than he realizes.
"I tried to throw the ball like him, tried to catch the ball like him," Chapman said. "I kind of started my craft there in high school and followed his lead a little bit, then tweaked it for my own. We definitely have similar actions; he might do a little bit more of a jump-throw on the backhand and I do a little bit more of a fadeaway throw."
For Arenado's part, though he doesn't know the granular details of how the DRS stat works, he's aware that he's far lower this season than he has been at this point in seasons past (his DRS each of the past two seasons was 20). He has a theory as to why.
"I feel like it's been a completely different year [defensively]," said Arenado. "I feel like I'm not diving as much. Earlier in the year I was diving a lot, but [not as much since]. Maybe it's shifts and stuff. But that's just the way it goes year to year. I don't know how some of these stats work.
"I feel like I have been making some plays, but I definitely wish I had the chance to make more 'web gem'-type plays. I want the ball hit to me. I feel like lately I haven't gotten a lot. But baseball's like that; you've just got to continue to stay ready and put the work in."

As they prepared to take the same field on Friday, it wasn't lost on either player what was transpiring.
"He thinks I'm better than him at what?" Chapman said with an incredulous smile when informed of what Arenado said earlier.
"I haven't done one thing he's done yet. I do feel that I'm good enough to do some of those things, but you've got to prove it."
Chapman is certainly in the process of proving it, and Arenado is proven. Both from the same high school, and now both the premier defensive third basemen in the Majors, their careers have now officially intersected.
"It's nice to be able to play Nolan," Chapman said. "His family's here, and my family's here, and they're all close. It's gonna be a cool series."