They did this by proving their mettle against other cellar-welling teams, recently winning a series, 2-1, against the Colorado Rockies, and clinching another series, 3-0 (so far), against the Washington Nationals.
(A loss to them tonight would not change the series result.)
The latest coup was a narrow, 2-1, victory last night over the Nats. The Pirates have held opponents to one, and even zero points before, but never when those scores were only one less than their own.
Now the Pirates have proven that they can win "efficiently" (with few extra runs).
The story would have been even better if they had held on for a 1-0 victory against the Rockies last Friday, instead of losing 3-1 in the ninth.
But given the twists and turns of that series, the Pirates did well to win it, 2-1, because any one of those games could have gone either way.
The Pirates were also lucky to be 3-0 against the Nats, because of the first three games of the series were also tight.
But the Pirates are now close to .500 because of how well they have done against other sub-.500 teams.
On the season, they are (so far) 3-0 against the Washington Nationals, 3-0 against the Florida Marlins, 2-1 against the Colorado Rockies, and 2-1 against the San Diego Padres. They're also 2-1 against the Atlanta Braves, who are barely above. 500.
Only the Houston Astros, among sub-.500 teams, have won more games against the Pirates than they have lost (2-1). And the Astros are nearly at .500 themselves.
On the other hand, the Pirates have a dismal to mixed record against most over-.500 teams: 0-5 for the season against the Milwaukee Brewers and 0-3 against the New York Mets; 4-5 against the St. Louis Cardinals and 2-3 against the Cincinnati Reds.
In this regard, the Pirates may soon become the definition of mediocrity; the team yours must beat if it wants to be "good." Mediocrity isn't great. But it's a decided improvement over where the Pirates are coming from.