There has been a running belief around some people within the Dodgers organization in recent seasons, a theory about their Southern California rivals that sprouted two Octobers ago and has been crystalized in a tightly-contested division race this year.

When the Dodgers play the San Diego Padres, they seem to typically get the Padres’ best.

And when the rivalry ratchets up, the Padres’ intensity tends to go highest.

It was certainly true in the 2022 playoffs, when the underdog Padres stormed to a four-game National League Division Series win over an 111-win juggernaut Dodgers squad.

It manifested more subtly last year, with the Dodgers forced to grind out a number of close rivalry game wins despite finishing well ahead of the Padres in the standings.

And it has been undeniably clear so far this season, one in which the Padres have taken seven of 10 head-to-head matchups and trimmed a once nine-game division lead for the Dodgers down to just three entering the season’s final week.

“They’ve had their way with us up to this point,” manager Dave Roberts said Sunday.

So, ahead of a pivotal three-game set against the Padres this week at Dodger Stadium that kicks off Tuesday night, Roberts not only highlighted the dynamic — but challenged his team to offer a response.

“I think it’s pretty easy to see that when we’ve played them, I think 10 times this year, they came out more intense than we did,” Roberts said. “And that’s got to change. I expect it to change. Playing those guys — in certainly very, very meaningful games — will bring out the best in us.”

Or so Roberts can only hope.

Meaningful might be an understatement for what’s at stake this week.

If the Dodgers win the series, they’ll clinch their third straight NL West title and 11th in the past 12 years, and very likely assure themselves of an all-important first-round bye.

By winning one of the three games, the Dodgers would still control their own destiny entering the season’s final weekend — though they’d have work remaining with a magic number of two going into their closing series against the Colorado Rockies.

And if they Dodgers get swept by the Padres, they’d suddenly be on the back foot: Technically tied for the division lead with three games to go, but knowing they’d lost any end-of-season tiebreaker for the division title because San Diego has already clinched the edge in head-to-head record (the first time they’ve done that against the Dodgers since 2010).

“Obviously they get up to play us, and they’ve played well,” Roberts said of the Padres earlier this season.

And how can the Dodgers combat this week?

“For us, I just want the mindset to be, stay on the attack,” Roberts said. “We’re not chasing anyone. And you can’t go into careful, defense mode.”

To Roberts, that mentality hasn’t always taken shape in the Dodgers’ previous meeting with the Padres this season.

After beating San Diego 5-2 on opening day in an international trip to Seoul, South Korea, the Dodgers lost the second leg of the series in a sloppy 15-11 defeat, one marred by Yoshinobu Yamamoto’s disastrous MLB debut.

A few weeks later, the Padres came to Los Angeles and won just their third series at Chavez Ravine in the last five years.

Two subsequent visits to San Diego didn’t go much better for the Dodgers, who were walked off and shut out in a series loss at Petco Park in May, then swept in a two-game set at the end of July.

“I think the chaser always seems like they have a little extra incentive, so I think that’s part of it,” Roberts said of the intensity gap he’s observed at times between the clubs. “But the talent being equal, there’s no reason why our fight, our intensity, focus shouldn’t match theirs or best theirs.”

While the Dodgers haven’t pitched great against the Padres (they have a 4.62 team ERA against San Diego this season), the club’s biggest problem in the rivalry this year has come at the plate.

The Dodgers’ .602 OPS against Padres pitchers is their lowest mark against any team this season. And on multiple occasions this year, Roberts and others have alluded to the idea that the Padres aren’t intimidated by the Dodgers’ star-studded lineup, familiar enough with them to know how to avoid danger and collect outs.

“We have to be proactive and continue to stay on the attack,” Roberts said on Sunday afternoon, of the team’s general mindset entering the season’s final stretch. “So that’s kind of my message.”

The fact this week’s series matters to the standings at all is a testament to San Diego’s second-half resurgence, in which it has posted the best record in baseball (40-17) since the All-Star break.

As a result, the pressure is on the Dodgers to hold them off now, and avoid the added complications that would come with squandering the division crown and taking the long route through the playoffs — especially for a team already short on pitching.

“It’ll be fun, a lot of energy,” outfielder Mookie Betts said. “I’m sure a lot of emotions and whatnot. These are the games we dream of playing.”

And ones that, at this point, could lead to a nightmare scenario if they lose.

“Those guys are playing great,” Roberts said. “But … I feel like we can still continue to be aggressive and go out there and try to win a series.”