It’s not exactly a skill, which is good considering the makeup of the Bulls’ roster. And it’s tough to measure, so there’s no way of knowing exactly where they rank among other teams. But its results can be easily seen, and in a year where the Bulls have swapped out talent for youth, they’re discovering an energy and passion that’s suddenly resulting in unexpected victories. The Bulls moved their winning streak to three games on Monday night against a tired and depleted – and yet still far more talented – Celtics team, earning a decisive 108-85 victory that displayed just how much this team still cares. Granted, caring alone and playing with energy won’t have them playing in May or June, but good habits being formed by young players give some optimism for the future. It was everywhere on Monday night. A letdown of sorts from the Celtics could have been predicted. Boston was playing its third road game in four nights, and the first two (San Antonio on Friday, Detroit on Sunday) were anything but easy. MVP candidate Kyrie Irving was resting a quad contusion and even Al Horford (knee) wasn’t cleared to play until about 20 minutes until tip. But talent alone still could have pushed the Celtics ahead against an inferior Bulls team. With young wins Jayson Tatum and Jaylen Brown, a backcourt of Marcus Smart and Terry Rozier, and 30 minutes of Horford the Celtics were still equipped to get by a Bulls team that entered Monday with the league’s worst record. But it didn’t happen. The Bulls were far more aggressive, contested jumpers that Boston wouldn’t, played passing lanes and went after loose balls that the Celtics watched more often than not. Boston took 40 3-pointers even without Irving (and Marcus Morris), and they committed 15 turnovers. It was sloppy throughout, and the Bulls took advantage.