By Matthew Geagan, CBS Boston

BOSTON (CBS) — The Celtics dropped their fourth straight Wednesday night, falling to the Cleveland Cavaliers to secure a spot in the NBA play-in tournament. It’s not a spot anyone saw Boston finishing in when the season began, but that’s what happens when a team loses to a lot of bad teams.

In losing to the Cavaliers, the Celtics lost their season series against Cleveland. The Cavs are, by no uncertain terms, tanking this year. And the Celtics lost two of their three matchups against that tanking team.

It happens, right? Sometimes, one team just cannot beat another, no matter how bad that other team may be. But for the Celtics, those kinds of losses were the norm. No team was afraid to play the Celtics, even the ones that flat out stunk. Even teams that hadn’t won in weeks got the best of Boston, as the Cavs snapped an 11-game losing streak on Wednesday night.

Do the math, and you come out with this: The Celtics are a bad team themselves. They now sit at 35-35 and could very well finish the season under .500. A season-ending six-game losing streak is not out of the realm of possibility, and another loss or two (there is no guarantee the Celtics finish in that 7-8 matchup) in the play-in round could mean the Celtics fall into the lottery.

How did it get to this? Injuries and COVID did not help, but teams deal with injuries and all teams had to deal with COVID this season. The real culprit is Boston’s putrid defensive play, and their even more putrid play against teams at the bottom of the standings.

Here’s a look at how the Celtics faired against the worst of the worst in the NBA. (Turn young children away at this point):

Cleveland Cavaliers, 22-48: Lost two of three

Chicago Bulls, 29-40: Lost two of three

Oklahoma City Thunder, 21-49, : Lost one of two, but that one loss snapped a 14-game losing streak for the Thunder, who have proceeded to lose eight straight since that win.

New Orleans Pelicans, 31-39: Lost both games

Sacramento Kings, 31-38: Lost both games

Washington Wizards, 32-38: Lost one of three, but that one loss may be Boston’s worst loss of season (there’s a lot of competition in that department)

San Antonio Spurs, 33-36: Split two-game series, needed furious comeback and 60 points from Tatum to win

Detroit Piston, 20-50: Lost two of three

That is 13 losses to teams outside the “playoff” picture, though the Wizards and Spurs are both in the play-in tournament. However, we all know that being a play-in team does not make one a playoff team. Just ask the Celtics.

Winning six of those games would have put the Celtics comfortably in the top four of the Eastern Conference. Winning even four of them would have kept them out of the play-in tourney.

But the Celtics didn’t show up in most of those games, and now they’re a pretend playoff team that could be sent home before the real postseason begins. That would be a really bad ending to a really bad season for a really bad team.