As early as tonight, long-suffering fans of the Pittsburgh Pirates will lay hold of something they haven’t been able to claim in more than 20 years: a winning season.

It’s been a long wait: two decades without a winning season is the longest in history for any professional sports team in North America.

But the wait is nearly over. With 137 of their 162 games played so far in 2013, the Pirates have won 80 games and lost 57. That means they must win just one more of their remaining 25 games to clinch a winning season.

It’s a shame the win is certain to come while the Buccos are on the road. They play tonight and Wednesday in Milwaukee, have a weekend series in St. Louis and then play the Texas Rangers in Arlington, Texas.

The fans have supported the Pirates’s turn-around effort. Paid attendance at PNC Park topped 2 million last year for the first time since 2001, the year it opened. It’s on pace to top 2 million again this season.

It’s hard to remember an entire generation has grown up not knowing the thrill of a Pirates pennant run or appearance in the World Series. The heyday 1970s, which began with the legendary outfielder Roberto Clemente and closed with Willie “Pops” Stargell and “We are Family,” was 30 years ago.

The Pirates’ last winning season and playoffs run was in 1992, the same year star outfielder Barry Bonds left the team as a free agent to join the San Francisco Giants. The organization has been adrift ever since then, reaching a low point with 105 losses in 2010.

Now they’re division leaders.

The turning point began three years ago with the appointment of Clint Hurdle as manager. The team has been blessed with superb pitching: The team’s .317 earned-run average is best in the majors.

Of course, the Pirates and their fans want to accomplish more than just a winning season — especially after a 21-year drought. Older fans recall the glory years of the 1970s, Clemente and Stargell, and a heritage of winning. Founded in 1882 as the Pittsburgh Alleghenys, the Pirates have five World Series championships to their credit along with nine National League championship pennants and 14 playoff appearances.

Will the 2013 Pirates rank among those best teams and those most memorable seasons? It might be too soon to tell. But for fans who have waited this long for a winner, patience is the ultimate virtue.