HOUSTON -- For the first five weeks of the season, the Astros' offense has been a study in contrasts.

After having one of the lowest team batting averages in baseball for most of the first three weeks of the season, the Astros hit .281 (115-for-409) with 17 homers, 44 extra-base hits and 71 runs scored in their last 12 games entering Sunday's series finale against the Brewers. During that span, the team batting average has risen 21 points, from .229 to .250.

The Astros rank among the top 10 teams in baseball in batting average, slugging percentage (.423, ninth) and runs (144, tied with the Phillies for ninth). They lead the National League with a .302 batting average with runners in scoring position. Only the Athletics (.320), Angels (.314) and Red Sox (.306) have fared better.

On the other hand, Houston's 81 walks are the fewest in the league, and the team on-base percentage of .306 ranks 29th in baseball, ahead of only San Diego (.302).

So is this the typical Astros offense we're seeing now or was the former more in line with what we can expect?

"I'll just put it this way, and it's what I've always said, and it's that I'd just like to see a little consistency," manager Cecil Cooper said. "Not complaining that it hasn't been good. We've been productive, we're scoring runs, but consistency like [Saturday] night when we get five and pretty much shut it down after that, and that's what I'm talking about. We've got good hitters in our lineup. We didn't really put them away when we could have."

Cooper isn't concerned about the low walks totals and on-base percentage. This is a team that swings the bats; as long as they aren't striking out too often, the Astros can live with fewer walks.

"That's not my concern as much as continuing to fight and not have three-pitch at-bats, two-pitch at-bats, unless you're getting something good to hit," Cooper said.

In any case, the Astros are optimistic the best of this offense is yet to come.

"I don't think we've put it all together yet," first baseman Lance Berkman said. "We didn't have [second baseman Kazuo Matsui] most of the first month, and we just got [third baseman Ty] Wigginton back. We've also got some young guys who are just going to get better, in my opinion, the more games we play."

Shortstop Miguel Tejada, who entered Sunday's game with an eight-game hitting streak, agrees the offense has room to improve.

"This is a very good offense," Tejada said. "Everybody can hit, hit for power. We've got guys who get on base and steal ... what we need to score a lot of runs. I don't think we've played as well as we can."

Not that the Astros are a wait-for-the-three-run-homer type of attack. They have power, obviously, and speedsters like Michael Bourn and Matsui at the top of the order that can get on base. The bottom three of the starting eight -- Hunter Pence, Wigginton and J.R. Towles -- have the potential to be the best lower third of the order this team has had in years.

Potentially, this team has what it takes to continue to put up crooked numbers on a regular basis. The key is that consistency that Cooper talks about.

"If we're going to be what we think we can be, just go ahead and get rid of them [opposing teams], put them away," Cooper said. "I'd just like to see our at-bats [be] at-bats where we're fighting."

Cooper points to the Rockies as an example as to what he'd like to see from Houston's hitters.

"They had so many 10-pitch, nine-pitch at-bats against us. I think we have the same kind of hitters, same kind of guys," Cooper said. "Good hitters need to eat pitchers up a little bit sometimes. Especially when we get them in position where we can do that."

A case in point happened Saturday night. The Astros, leading, 6-2, had two on and nobody out in the sixth inning with Tejada at the plate.

"He's been great driving in runs, but I think he had in his mind -- he said he wasn't -- but I think in his mind he was so set on trying to hit the ball the other way that he chased a high fastball and ended up hitting a little pop," Cooper said. "That could have been the inning to blow them out of there right there, but I think because he was so unselfish trying to go that way instead of being who he is and drive that run in.

"Sometimes I think that maybe we do that instead of being a little more patient and doing what we do. That's no knock on him, that just shows you what kind of player he is -- he's thinking about us [and to] move the runners at least. I think we need to do just a little better job of extending innings and adding on runs. We haven't really done that."