The Rockies open a three-game series against the Dodgers at Dodger Stadium on Monday night.

It’s a B-I-G series.

How big? Bigger than any other series the Rockies have played this year, and right up there at the top of the list of biggest series ever.

Sure, there are 13 games remaining in the Rockies season, and those 10 games after the Rockies and Dodgers get finished with their showdown this week will have meaning, too.

But this is a late September showdown between two teams battling for the NL West title. A half-game separates them, the Rockies holding the edge going into the series.

If the Rockies sweep the series they have a 3 1/2-game lead on the Dodgers, without needing help from any other team. If they win two out of three they will be 1 1/2 games up. But if they win only one of the three, they will be a half-game behind the Dodgers, two out of three and they are 1 1/2 back, and all three would drop them 2 1/2 back.

Why the big deal? Because that would mean, even if the Rockies were to win all 10 of what will be left on their regular-season schedule they would need help from other teams beating the Dodgers to be able to overtake the Dodgers for the first division title in franchise history.

Yes, wins in April and May and June and July and August all count the same as any other win. The catch, however, is that all losses are not created equal. When the Rockies stumbled in June, they could honestly remind the cynics that it’s a long season, and there was plenty of time left.

In the final two weeks of the season, it’s no longer a long season. There isn’t much time left to make up for games gone wrong.

The benefit for the Rockies is they do finish out the regular season with a seven-game home stand — the fading Phillies for four and disappointing Nationals for three.

The Rockies are 7-9 against the Dodgers this season. They have won four of their last six games against the Dodgers — but they were all played at Coors Field. They haven’t been to Dodger Stadium since losing a 6-4 game to the Dodgers on July 1. The Rockies, though are 3-3 at Dodger Stadium this year.

The Season Series

The Rockies do arrive with closer Wade Davis on a roll, having pitched 13 scoreless innings in his last 13 appearances, going 2-0 with eight saves in eight opportunities. And with the expectation that Seunghwan Oh will be available after missing the last week with a left hamstring strain, the Rockies have a solid three-man bridge from the rotation to Davis with Oh, Scott Oberg, and Adam Ottovino.

Oberg, in particular, has given the Rockies a late season lift, going 3-0 with a 1.42 ERA in his last 25 appearances.

The key, however, will be the Rockies rotation. Kyle Freeland, who has been the model of consistency, is scheduled to start Tuesday with Jon Gray on Monday and Tyler Anderson on Tuesday.

The Rockies are 9-1 in Freeland’s starts since the break. They are 8-2 in Gray’s starts, but concern has developed with his lasting only four innings each of the last two starts. And they are 1-9 when Anderson has started, although he was solid in a 2-0 loss at San Francisco on Friday.

The 3 Starters Since the Break

While the Rockies were shutout on Friday and Saturday — the first back-to-back shutouts of the season — the offense has had strong efforts this month. But two big bats have been silenced — Nolan Arenado, who is hitting .241 for the month (1-for-12 in the just-completed visit to San Francisco), and Carlos Gonzalez, is in a 3-for-25 slump that has dropped his September average to .146.

On the Offensive