Arizona’s J.D. Martinez is congratulated by teammates after hitting his fourth home run of the game Monday night. (Mark J. Terrill/AP)

Even before making his first trip to the plate Monday, J.D. Martinez was one of the most important players in baseball this year, a walking, talking symbol of where the game stands in 2017.

As an early and vocal convert to the Cult of the Fly Ball, Martinez helped push terms such as launch angle and swing plane into the hitter’s essential lexicon and bring about the airborne revolution that has baseball on pace for a record number of home runs this season.

In July, when the Arizona Diamondbacks acquired him from the Detroit Tigers to serve as lineup protection for Paul Goldschmidt, Martinez became arguably the best hitter to change teams at the trade deadline. And in August, as the Diamondbacks surged to what is now a 6 ½-game lead in the National League wild card race, he became one of the major reasons Arizona now appears to be as scary a postseason opponent as any team in the game.

Then came Monday. In four straight trips to the plate, against four different Los Angeles Dodgers pitchers, Martinez, 30, slugged four home runs, making history as the 18th player to accomplish that in a single game. Of course, this being the year of the home run, a feat that had occurred at a rate of roughly once a decade for much of the game’s history has now happened twice in 2017 — with Cincinnati’s Scooter Gennett having done it in June.

What has been dawning on the rest of baseball for the past several weeks is now glaringly apparent: the Diamondbacks, winners of 11 straight and 13 of their last 14, are at this moment the scariest team in the NL. And among the opponents who surely would not disagree are the Dodgers, losers of nine of their past 10 games — and a team that, despite its 12 ½ game lead over the Diamondbacks in the NL West, would want no part of them in the Division Series a month from now.


Robbie Ray wipes his face after giving up a single to the Dodgers’ Logan Forsythe in the sixth inning, breaking up a perfect game. (Mark J. Terrill/AP)

In four head-to-head meetings with the Dodgers over the past week, the Diamondbacks have won all four games by a combined score of 34-11, including a 13-0 rout on Monday that featured not only Martinez’s four-homer game but also a 14-strikeout performance by starting pitcher Robbie Ray. With a 9-8 season record against the Dodgers, the Diamondbacks are one of only two teams against whom Los Angeles has a losing record this year, the other being the Washington Nationals (1-2).

“They’re playing really well,” Dodgers Manager Dave Roberts told reporters Monday. “Us, not so well.”

The next time the Dodgers face Ray, the former Nationals prospect having a breakthrough season in Arizona, it would likely be in Game 1 of the NL Division Series, against Los Angeles ace Clayton Kershaw. With their spot in the NL wild card game all but assured, the Diamondbacks can line up veteran Zack Greinke to start that win-or-go-home game and, should they win, have Ray — 3-0 with a 2.27 ERA and 53 strikeouts in 31 2/3 innings this season against Los Angeles — ready to go against Kershaw in Game 1 and, if necessary, one more time in the series.

As for Martinez, he was already enjoying the best season of his career before the trade from Detroit to Arizona on July 19, but since then he has been scorching. His four homers Monday gave him 18 since joining the Diamondbacks, with only major league home run leader Giancarlo Stanton of the Miami Marlins having more in that span. Martinez has batted primarily in the fifth slot, behind Goldschmidt, for the Diamondbacks, but on Monday, with Goldschmidt out of the lineup with a sore elbow, he batted cleanup.

Three of the pitchers who surrendered homers to Martinez on Monday — starter Rich Hill and relievers Pedro Baez and Josh Fields — are expected to be part of the Dodgers’ postseason staff. Chances are, they will all see Martinez again — in October. It is something none of them, after what he did to them on Monday, will relish.

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