Just when it felt like it was time to remove the Cinderella crown from the A's, they go and lose three straight. They appeared ready to graduate from lovable underdog to legit World Series contender, but scoring 12 runs while batting .175 over a five-game stretch has delayed such an anointing.

They're still as formidable as they are lovable. But these next few weeks will be good insight as to whether the A's are real contenders or a sleeper squad with a pitcher's chance.

The A's looked every bit a favorite as recently as last week, when they became the first 30-win team in the major leagues. But they enter Sunday's series finale in Toronto looking to avoid a three-game sweep, looking to keep the hard-charging Angels at bay, looking to regain the rhythm that had them with the best record in baseball.

But cold bats and closer issues have the A's flirting with regression. The A's next 20 games are against teams currently above .500, including 12 on the road.

They are 0-3 in a stretch of 48 games in 52 nights before the All-Star break. When it's done, they will have played 18 games against Detroit, Toronto and the Giants -- all division leaders. Another 18 against the Yankees, Angels, Orioles and Marlins -- all in the thick of division races. Seven more against the Rangers and Red Sox.

If the A's reach the All-Star break still among the pacesetters in the American League, that's saying something. It may elevate this club to one of the most feared teams in baseball.

Even with the three-game skid, the A's have numbers that are elite. Their collective approach to run producing has turned a weakness into a strength before the recent slump.

Still, the A's lead the A.L. in runs, RBIs and on-base percentage.

The odd part about this run-scoring prowess is it comes after the A's spent their biggest chunks of change on pitching. They didn't go out and buy a big bat, yet their bats seem bigger.

The A's improved offense is a big deal because they still have the arms (closer issues notwithstanding). The continued growth of Sonny Gray and the addition of Scott Kazmir lead one of the best starting rotations in baseball. Even with pricey offseason acquisition Jim Johnson being a bust so far at closer, the A's still have one of baseball's best pitching staffs.

The A's lead the majors in batting average against, WHIP and opponents' OPS. Only the Braves have a better team ERA.

The result of top-notch pitching and great offensive production is this: the A's have outscored their opponents by 92 runs. Easily the best in the majors.

Now, we're about to see if it's all an early season fluke or evidence that the A's have taken it to a new level. If the bats remain cold against the stiff competition, if they can't figure out a reliable ninth-inning option on the mound, then maybe the feverish start was just a tease.

The prediction here is the A's will be fine. They will win more than their fair share when it's all said and done. What's important is maintaining the confidence they've shown to this point, especially at the plate.

At times this season, the A's have played with a swagger that suggests they know they can score at any time on anyone. The rhythm they had as a unit, the high-level execution of what they want to do at the plate, it seemed to create a psychological edge.

They can't lose that over this daunting stretch. For that could be the difference between an early ouster from the 2014 postseason and making a World Series run.

Read Marcus Thompson II's blog at blogs.mercurynews.com/thompson. Contact him at mthomps2@bayareanewsgroup.com. Follow him on Twitter at twitter.com/ThompsonScribe.