The American League’s slate of contenders coming into the season seemed reasonably set, at least to a lot of mainstream analysts. The Mariners had enhanced their bid to challenge the Angels in the West, the Yankees and Red Sox were supposed to do their usual six-month duel in the East, and the Central was supposed to be a tilt between those 1,000-run Tigers and the sabermetrically savvy Indians.

Whereas all of these assumptions have proven false, perhaps the biggest surprise, for stat-heads and old-schoolers alike, has been in the AL Central. While the Tigers blended a nasty case of the olds with a morass of injuries and under-performance, and while the Indians have struggled to find sufficient talent to surround a small group of star players, it’s the White Sox who are riding high, 6 1/2 games up on the Twins going into last night’s action, 71/2 ahead of the Tribe, and a solid 10-spot ahead of the Tigers.

How did that happen? Some of it has been the virtue of simple head-to-head happiness — the Sox have drubbed the favored Tigers and Indians, going 11-5 against them. Similarly, a 7-4 start against the Twins keeps them up on everybody, while the fact that they have played only one series against the Royals gives cause for confidence that the Sox haven’t even hit the softest portions of their schedule yet.

Getting hung up on these things, you run the risk of giving too much credit to the schedule-makers and not giving credit where it’s due: in the front office, in the dugout, and on the diamond. It’s easy to let yourself get distracted by skipper Ozzie Guillen’s quick temper and Dice Clay-like stylings off of the field, or general manager Kenny Williams’s lapses into defensiveness, but there’s a wisdom here that deserves credit, because it’s responsible for what we’re seeing in the standings. A team has been assembled that, just like the one that won it all in 2005, has the right combination of power, pitching, and an ability to pick it in the field that might be enough to embarrass everyone who gave them short shrift before Opening Day, now as then.

Although the Sox had big investments in starting pitchers such as Javier Vazquez, Mark Buehrle, and Jose Contreras, and also in sluggers such as Jim Thome, Paul Konerko, and Jermaine Dye, Williams had a team with an absence of quality players up the middle, dead spots in the lineup, and a bullpen that needed to add talent to handle winnable ballgames between the middle innings and closer Bobby Jenks. With that kind of comprehensive to-do list, what was achieved was nothing short of remarkable.

Although Williams was castigated after the Winter Meetings for not signing Torii Hunter and then also losing out on Andruw Jones, it was just as well, because finding a center fielder was just one problem among many. Williams’s multiple needs if he was going to be able to field a contender put him in a position to achieve something much more creative — he instead swung a deal with the A’s that landed his club Nick Swisher to fill the need for a center fielder. While expensive in terms of stripping the organization of many of its few remaining prospects, it didn’t handicap Williams’s ability to spend money to add much-needed help for his bullpen — notably top setup men Octavio Dotel and Scott Linebrink. He also still had the financial freedom (and his organization had the scouting acumen) to take a flyer on Cuban import Alexei Ramirez to fit somewhere in the lineup at an up-the-middle position, whether it was second, short, or center. In another move that proved controversial at the time, rather than settle for the OBP-challenged Juan Uribe at shortstop, Williams traded his overly defense-dependent fourth starting pitcher, Jon Garland, for Orlando Cabrera in a walk year. And in an especially underrated move, Williams traded with the Diamondbacks for former top outfield prospect Carlos Quentin when his value was down after an injury-marred 2007 season.

Across the board, these moves are looking inspired. Not all at once, but as an intelligent and sometimes overlapping collection of risks worth taking. Guillen favored Uribe initially as his second baseman, but when Ramirez got an opportunity to play in May, he won a lion’s share of the playing time at the keystone, reducing Uribe to an effective defensive replacement. Challenging Swisher with the responsibility of playing center made sure the outfield had space for Quentin to blossom as a pull-power slugger in left field (playing in a park that rewards it), and thus provided them with a stronger overall lineup that was no longer saddled with some of last season’s low-OBP water bugs in center. Even though Swisher’s struggled to get his bat started — as have Thome and Konerko — they’re still contributing to a lineup no longer stuck with easy outs by drawing walks. This year’s Sox team is on a pace to draw 576 walks, a big bump up from the 435 they drew in their championship season. That season’s team did its scoring on home runs — not small-ball tactics — hitting 200 of them. But even with cold starts from some of its key sluggers, this year’s team is just as reliant on the long ball — currently on a pace for 209 — but better able to make those souvenirs into crooked numbers on the scoreboard.

In the rotation, the Sox are reaping the rewards of last season’s investment of rotation time toward young starting pitchers such as John Danks and Gavin Floyd; they took their lumps last season, but now it isn’t just the veteran trio up front. Stability is also reflected in that, beyond one spot start, the original five starters are still taking their turns, which is why the Sox rank third in the majors in starter innings pitched. Every Sox starter has delivered a quality start more than half of the time out, and the rotation’s collective 43 quality starts in the team’s initial 65 reflects how reliably they’re delivering winnable ballgames as well as pitching deep into those games. While it remains to be seen if Contreras’s recent reliance on breaking stuff will help him remain a top starter, there’s enough depth to anticipate a real run at the division title.

Ms. Kahrl is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit baseballprospectus.com.