It’s game day!

The Diamondbacks are set to take on the Colorado Rockies in a NL West-only winner-take-all wild card showdown.

A single baseball game, perhaps more than any other major team sport, is unpredictable. That’s why they play 162 regular-season games and that’s why the fairly new playoff format with two wild card teams facing off for the right to move on is so fascinating.

Between home-field advantage, a better regular-season record and a stronger ace pitcher on the bump tonight, the D-backs are favored to advance and face the Los Angeles Dodgers in the National League Divisional Series starting this weekend. But it’s a close call -- an argument could be made for either team.

Here to make the case for Arizona is Valley native Hayden Packwood. Arguing for the Rockies will be Michael Nowels, who is from the Denver area.

Hayden: First off, two numbers you need to be aware of 6 and 81. Six games. SIX games the D-backs had on the Colorado Rockies. Plus, the D-backs took the season series. And that 81? That's how many combined home runs JD Martinez and Paul Goldschimidt have. Arizona's bash bros. Not to mention, Goldschimidt's multi-HR game against the Rocks earlier this season and the fact that Jon Gray has basically been throwing batting practice to Martinez the last few times they've faced each other.

Michael: Sure, Arizona's bash bros can mash some dingers. But the Rockies' top two performers are nothing to sneeze at. Charlie Blackmon is the first leadoff man in major league history to reach 100 RBI and Nolan Arenado mixes a powerful bat with the best hot-corner glovework in the game (sorry, Manny Machado). As great as Martinez has been since coming over from Detroit, Goldschmidt suffered an icy September, with a dismal slash line of .175/.256/.313 last month. Meanwhile, Fangraphs ranks Blackmon (No. 5 in the NL) and Arenado (No. 8) ahead of either Diamondback in wins above replacement.

Hayden: Goldschmidt has been cold lately. You're right. But I expect your beloved Rockies to be the same temperature against Zack Greinke. A game like this with so much on the line... That's exactly why you have Greinke. That's why you spend so much money on an ace pitcher. Sure, he's had some spotty starts against the Rockies as a memeber of the D-backs (we'll leave the "Story" about last season's Opening Day for another time), but he's had a great year. He's held the Rockies to 2 earned runs in nearly every start this season and in all but one of those, racked up 7 innings pitched.

Michael: You may argue Greinke's been rock-solid against the Rox, but the cracks in his game might be showing. His only home loss of the year came against Colorado on Sept. 11, and he hasn't lasted more than four innings in either of his last two starts. Plus, while he's largely handled Blackmon and Arenado, the suddenly resurgent Carlos Gonzalez eats Greinke's pitching for breakfast (usually before a patented bat drop). He's gone 14-for-42 against the D-backs ace in his career, including 5 homers. Plus, that Story you mentioned (or asked not to mention) is 8-for-24 with 4 dingers of his own against Greinke.

Hayden: Before you go off celebrating "Rocktober," last time I checked the Diamondbacks are pretty good when faced with an elimination game at Chase Field. And once Greinke steps off the mound -- well, the team's got the best beard in the bullpen, and do you remember Martinez against Gray? "Just Dingers."

Michael: Don't discount the Rockies' pen! Though the rookie-laden starting staff got most of the headlines, Greg Holland has returned to his near-perfect first-half form after a rather large midseason hiccup. And perhaps you're forgetting the last time these clubs faced off in the playoffs (insert broom emoji). Oh by the way, that came just after the last time Colorado faced a winner-take-all scenario. From right field at Coors, I watched Matt Holliday slide over home plate, and he definitely touched it. I'll be playing the right field seats again tonight.

Whether you're at Chase Field decked out in Rockies gear or there screaming your head off for the Diamondbacks -- it should be a game to remember. Two of MLB's best, MVP-caliber players on the national stage. It sold out in roughly an hour for good reason.

The entire season comes down to one game tonight: Colorado vs. Arizona.