The Boston Celtics beat the Bulls by 56 points the last time they played in Chicago on Dec. 8.

Granted, Chicago is a different team since that point, and winners of its last three games, but there is no way to cut the Celtics’ 126-116 loss to the Bulls than as a black eye.

It’s hardly the first time this season the Celtics have let a game they were heavily favored in, or held a massive lead in, get away from them. Boston has defined inconsistency at times, following up Thursday’s gutsy performance against the Milwaukee Bucks with a clunker in Chicago against a team that entered with 15 wins and was on the backend of a back-to-back.

There clearly are things to be sorted out for the Celtics, and after the loss, Brad Stevens started with himself.

“At the end of the day, and I have said this before, I am disappointed in myself. And I have got to do a lot better,” Stevens told reporters after the game, as seen on NBC Sports Boston’s postgame coverage.

Stevens has shouldered the weight following losses like this in the past, including after the Celtics’ loss to the Los Angeles Clippers when they blew a 28-point lead.

“Hasn’t gotten much better has it?,” Stevens said. “I gotta do better. I just got to do everything. I gotta make sure we are playing better on offense. We can’t let our transition slack like that. We gotta defend with more purpose and more intensity on the ball. We can’t have those runs against us like what happened in the second and third quarters. There is a lot to do.”

The bench boss did not point to a lack of effort or intensity as a root cause in the loss.

“We played really hard the other night,” Stevens said of the one-point loss to the Bucks. “You’re going to have clunkers in the NBA. One of our disappointing parts of our season has been that we have let some games go that we played really well to start.

“We’re 60 games in, this is not a small sample as we have said before. Again, I have to do better.”

Here are some other notes from Saturday’s Celtics-Bulls game

— Chicago’s Zach LaVine (42) and Lauri Markkanen (35) each finished with career highs in scoring.

— The Bulls out-rebounded the Celtics 49-32. Boston did not reel in a single offensive board in the first half, and was topped 11-6 on the offensive glass.

— After a strong opening quarter, Boston’s defense fell apart, allowing 36 points in the second, 30 in the third and 32 in the fourth. Stevens pointed at the Celtics’ transition defense, which broke down in the second quarter, where the C’s were outscored 36-18.

“We let them get awfully comfortable,” Stevens said. “I thought in the first half, our transition defense was really bad. Obviously the start of the second, we didn’t give ourselves much of a chance. But they had to make the shots and they did.”

— Kyrie Irving recorded his 15th double-double of the season with 37 points and 10 assists. He was the only Celtic to finish in the positive at plus-4. Terry Rozier (16 minutes, three points) was minus-16.

— The Celtics have lost both games out of the All-Star break, and now are 14-15 on the road.

Thumbnail photo via `Kamil Krzaczynski/USA TODAY Sports Images