The Bulls are the worst shooting 3 point team in the league by percentage and only 4 teams take fewer 3s per game than the Bulls. No team takes as many 16-23 foot jumps as the Bulls. In fact, the next closest team, Minnesota, shoots 3 (!) less per game than the Bulls. This is even more outrageous when you consider that the Bulls are in the bottom 8 in the league in pace (averaging 2.5 fewer possessions per game than league average), so that a huge percentage of their shots per game are 16-23 foot jump shots. Even more discouraging is that the Bulls don't even shoot that shot better than average. The average rate of makes in that range is 38.5% leaguewide, but the Bulls make them at a rate of just 37.1%.
The Bulls also take the 5th fewest shots at the rim and are the 3rd worst team at finishing at the rim. They are 13th in shots taken in the under 10 foot range, but they are making 50% of these shots, good for the 4th highest percentage. They are also 13th in attempts in the 10-15 foot range, but they are 9th in FG% on shots in that range.
From this it's pretty clear why the Bulls are 26th in offensive efficiency. They don't get to the rim very often and are pretty bad at finishing at the rim. They don't take many threes and they are also the worst team in the league at making the threes they do take. They take more long 2pt jump shots (the game's least efficient shot) than any other team and make that shot at a below average percentage. The Bulls are actually pretty good at scoring inside when it's not at the rim (i.e. from 1 to 15 feet out). So it's pretty clear that they need to be attacking more and trying to get more shots in that area, and they also need to get to attack so that they can get to the line more, as they are 23rd in FT-r.
The good news is that there's a LOT of room for improvement from the offense. The bad news is that Vinny is our coach.