The 2005 season has been flying by, perhaps accelerated by lower scores and, to my mind, the greater number of strikes being called. The arrival of June, however, means that it’s time to start taking so-called “surprise teams” seriously. The American League’s three divisions are each led by one, and if the season ended today, only the Twins would repeat as a playoff team in the junior circuit.

While the White Sox’ and Orioles’ success stories have garnered widespread attention thus far, the Texas Rangers have climbed to the top of the A.L. West largely unnoticed. The Rangers used a nine-game winning streak at the end of May to sneak past the Angels into the division lead, a run that included a sweep of the mighty White Sox. Their 32-23 record is legitimate, despite any grumblings you might hear about a favorable schedule.

When you think of the Rangers, you think of their offense, and rightly so: Texas leads the major leagues in runs scored and home runs. In recent years, though, the Rangers’ reputation for fielding strong offenses was largely the result of playing in a hitter-friendly park. In truth, they haven’t been an above-average AL team at the plate since 2002, largely because a strong core, especially in the infield, has been dragged down by sub-par performances and lousy depth elsewhere.

This year, though, David Dellucci’s dream season (.268 AVG/.435 OBA/.528 SLG) has given the Rangers the on-base boost at the top of the lineup – and from an outfield corner – that they’ve lacked for the last two seasons. With Kevin Mench playing well in a regular role (.300/.358/.588), the Rangers’ lineup is seven deep. That’s hoisted them from a below-average offense (11th in the AL in OBA last year) to a good one, and from an AL West trailer to its leader. Perhaps most important, the Rangers’ core hitters – Mark Teixeira, Michael Young, Alfonso Soriano, and Hank Blalock – are all meeting expectations.

Upon a thorough inspection, though, the Rangers are in contention mostly because they’ve become much better at keeping the opposition off the scoreboard. Their raw total of 249 runs allowed is good for fifth in the AL.That ranking improves when you consider that Ameriquest Field is known as an excellent hitters’ park.

The credit for this improvement has to go to pitching coach Orel Hershiser. Without a significant amount of talent to work with, Hershiser has been able to get the Rangers to pitch a bit … well, a bit like Orel Hershisher did back in the late 1980s. Forty-year-old Kenny Rogers (8-2, 1.62 ERA) is pitching out of his mind, while second-year starter Chris Young has impressed with a 3.03 ERA in 65.1 innings.

The Rangers have allowed just 39 home runs this year – the fewest in the AL by nine – an amazing feat given their home park. They’re tied with the Twins for fifth in lowest slugging average allowed as well, a number that could be lower if only they had a better outfield defense (their 122 doubles and triples allowed is the second-highest total in the league; the blame is shared by the outfielders and the park). These figures are the result of Hershiser getting his charges to keep the ball on the ground. The Rangers are fourth in the AL in groundout/flyout ratio.

The Hershiser influence is less apparent in the other indicators. The Rangers are in the middle of the pack in walk rate and have a below-average K/BB thanks to a strikeout rate of just 5.72 K/9. Again, this is in part by design – the Rangers have a ball-in-play staff that wants to let the infielders make plays – but also reflects a lack of raw pitching talent that may be the team’s biggest weakness. Still, if you can allow the fewest homers in the league while playing in one of the league’s best home-run parks, you’ve got a head start to success.

This isn’t the AL West of 2000-04, after all. The A’s are stuck in the cellar and are going to be hard-pressed to get back to .500, while the Mariners aren’t likely to contend behind a dismal pitching staff. The Angels boast a much deeper and more effective pitching staff than do the Rangers, but they can’t match the Rangers’ offensive capabilities, even with Vladimir Guerrero in the lineup. It might take just 87 or 88 wins to win the division, and the Rangers are well-positioned to reach that number.

Offensively, the key for the Rangers is whether the surprise hitters – Dellucci and Mench – can sustain their performance and their playing time. Neither player has hit at this level before and, perhaps more to the point, neither has shown the ability to stay healthy for a full season. If they can, this lineup could very easily finish the season with the most runs in baseball.

The pitching side is a bit more complicated. The extremely low strikeout rate is tempered by the high groundball rate, and both are the result of the Rangers’ collective approach. However, because the Rangers walk an average amount of hitters, have a fairly large gap between the quality of their infield defense (good) and outfield defense (not so good), and play in a home park that is good for home runs, any drop in GB/FB ratio is going to be penalized swiftly.

If the Rangers want to extend their season into late October, it may come down to what roster additions they can make to supplement a solid foundation. It’s worth remembering that Texas GM John Hart has a history of failing to add the final pieces to championship puzzles. In Cleveland during the late 1990s, Hart was never able to make the trade to put the Indians over the top.

At last year’s trade deadline, the Rangers were in contention, yet Hart failed to add help in the outfield corners or on the pitching staff. Now again in 2005, Hart has a team that is good, but with obvious holes in the back of rotation and behind the plate. If filled correctly, new additions at these spots could add critical wins in a close race. But simply relying on Dellucci, Rogers, and reliever Brian Shouse (2.11 ERA, .162 batting average against) to continue their career years is a recipe for failure.

The Rangers are going to score enough runs to contend, and they should be able to prevent enough runs to contend. Whether they win when it matters, however, may depend entirely on Hart’s ability to do what he couldn’t do last year, and what he rarely did in Cleveland: improve the team at midseason by leveraging future value for present value.

Mr. Sheehan is a writer for Baseball Prospectus. For more state of the art commentary, visit baseballprospectus.com.