ARLINGTON -- Get the picture: Should the Rangers win on Sunday, they will hold their biggest lead in the AL West. Ever.

That's how big the margin has grown.

On Saturday, the Rangers dismantled the Houston Astros. Again. This time it was 12-4. It was Nomar Mazara, Mitch Moreland and Robinson Chirinos doing the battering of Houston pitching. It was the third consecutive game in which the Rangers have reached double figures in runs scored and their seventh straight win. It improved the AL West lead to 101/2 games with 26 remaining.

The Rangers once led the division by 11 games in 2010. For a day. That's the only occasion when they've had a bigger lead than they currently hold.

"And I view it like it's zero," manager Jeff Banister said. "Now is not the time to look up at where it is or what it is or how it is. We will continue to play good baseball and not look up."

Oh, they will look up, though. At least long enough to see the schedule.

They will see they are in the midst of 25 straight games (there are 20 more to go) against the AL West. And that should give them great confidence. They have absolutely owned their intra-division opponents this year. The last week is a prime example, with five consecutive wins over the two teams closest to them (first Seattle, then Houston).

It extends beyond that, though. The Rangers are 37-19 against the West, including a 13-2 mark against the Astros. They have won 10 consecutive intra-division games. And if you go back to last year, when the Rangers and Astros had their little dustup in Houston in which Banister and Houston manager A.J. Hinch came chest to chest, they are 62-35 in the division. For all those doubters, those who point to one-run wins and luck and the "regression to the mean," the Rangers have a run differential of plus-94 in those games.

Since then, Banister has had a shouting match with Seattle counterpart Scott Servais, too. And he's not about to shy away from any other comers.

Banister, a former Pittsburgh player and coach, learned from his NL Central roots and the chippy rivalries there that having an attitude inside the division is the first step toward owning the division.

"It was a bloodbath every night," he said. "It seemed like you were playing inside the division every night. You had to have an edge and an attitude. You compete against everybody, but these are the guys you have to beat. There are going to be some mundane days over the course of a 162-game season, but the division rivalry there is real and you need it. It was fun.

"I think our guys are ultra-aware of it and understand it," he added. "I think there is always a little extra something when we play inside the division."

Said shortstop Elvis Andrus: "We understand that these games are twice as important. We come to the field ready to play. We take the challenge the right way. I think that's why we are playing so well right now."

And while winning the AL West may already be settled, the next 20 games against division rivals and a final six against Milwaukee and Tampa Bay are still exceptionally important.

The Rangers began Saturday with a three-game lead over Cleveland for the AL's best record. The Indians and AL East leader Toronto still have their own division races on their hands, providing plenty of motivation to remain focused.

The Rangers play the final 15 games of the year against teams with no hope of even a winning record. If they clinch the division early and drift off, they could lose home-field advantage. That could mean the difference between playing the wild-card winner, which would have its ace available only once in a five-game series, or potentially facing Toronto in an emotionally charged series.

In case anybody forgot: Game 5 of last year's AL Division Series, which very well may have been impacted by the crowd, was played at Toronto.

The AL West lead may be growing obscene.

But the race that matters now remains tight.

Twitter: @Evan_P_Grant