Minneapolis ? The Chicago White Sox went from 99-63 and an 11-1 run through the postseason in 2005 to 90-72 and a third-place finish in the American League Central in 2006. The dropoff was followed by last season’s collapse to 72-90 and a fourth-place finish.

The assumption this spring was the White Sox’ time had come and gone and the Central now belonged to Detroit and Cleveland.

So much for assumptions.

The White Sox arrived in the Metrodome on Monday night with a 59-44 record (fourth best in the AL) and holding a 21â2-games up in the AL Central.

How is that the White Sox – a team with a veteran nucleus – could go in the tank as they did a year ago and now again have the look of a playoff team?

“We played down to our record last year,” catcher A.J. Pierzynski said. “The way we played, we deserved to be 72-90. The front office went out and made some changes.

“The biggest thing is our pitching. The general manager (Ken Williams) went out and put together a more experienced bullpen. We’ve been good from the pen to the back.

“And then (Gavin) Floyd and (John) Danks emerging as they have as starters – that’s been huge.”

Williams’ major acquisitions for this season were shortstop Orlando Cabrera, left fielder Carlos Quentin and outfielder/first baseman Nick Swisher. Quentin has been phenomenal, Cabrera stabilized the infield and Swisher has been effective, even with his low batting average (.228 entering Monday).

The White Sox also caught a break with the arrival of Alexei Ramirez, a 26-year-old at second base. He defected from the Cuban National Team last September during a tournament in the Dominican Republic.

The bullpen veterans who have made a difference in front of closer Bobby Jenks are Octavio Dotel and Scott Linebrink (currently on the disabled list). Dotel has a 2.91 ERA and 68 strikeouts in 461â3 innings.

This is Pierzynski’s fifth season since he left the Twins and his fourth in Chicago. He’s again catching 80 percent of his team’s games. At 31, he remains a rugged presence behind the plate and a difficult out.

On Monday, he was batting second for the 52nd time in manager Ozzie Guillen’s order.

“I’ve gone from being in an RBI position to trying to be on base for the guys in the middle … I just want to make sure I get Orlando (Cabrera) to third base with one out, if the chance is there.”

Pierzynski was talked up by the White Sox and by the fellows on ESPN as a catcher deserving of a place on his third All-Star team. He was selected as a member of the Twins in 2002 and of the White Sox in 2006.

He lost out in the players voting to Boston’s Jason Varitek, a player hitting 80 points below him. Disappointed?

Pierzynski shrugged.

“It would’ve been nice to be there, especially since I grew up in New York,” he said. “I knew how it was going to turn out, though.”

He gave a stoic impression and said: “I know it’s a popularity contest, and I don’t win many of those.”

What Pierzynski has won in Chicago is a World Series, and his White Sox look like the logical Central team to get another swing at it in October.