The Atlanta Hawks are a good team, if you look at the win-loss ledger. Atlanta's on pace to go 46-36 on the season; that will assuredly earn the Hawks the No. 5 seed in the East and a first-round date with the Orlando Magic. To finish the season 10 games over .500 would definitely qualify the Hawks as good.
But if you look at points margin, which is empirically a better measure of team performance, the Hawks are ... not good. In fact, the Hawks (who lost to the Chicago Bulls by 33 on Tuesday) have the points margin of a sub-.500 team. That's a huge difference! And if we defined a "good" team by one who wins, say, 45 games in a season, then the Hawks are getting awful close to becoming the worst good team in history.
Since the merger, eight teams that finished with a winning percentage of .549 or better -- that's no worse than a 45-37 record -- have had a points margin below break-even zero. The Hawks' current margin is -0.31 points per game; among these 45-win teams, only three are worse. The weird 2007-08 Cavaliers had a points margin of -0.35, as did the 1996-97 Orlando Magic. The infamous 2004-05 Wizards were -0.33. The Hawks are clustered there; four other teams, ranging from the 48-win '95 Lakers to the 45-win 2000 Raptors, fill out the short list.
Given what we saw Tuesday, the Hawks could very easily surpass the others and become the worst good team ever. Awesome!