On a Heartbreaking Night, Isaiah Thomas Showed Why the Celtics Need Him

Sunday night's playoff opener against the Chicago Bulls was the most difficult game, in some ways, of Isaiah Thomas's career. His younger sister, Chyna, had been killed in a car crash earlier that weekend. Thomas decided to play in Game 1, but he was visibly grieving on the court. It was heartbreaking to watch.

And given the pain he was going through, Thomas's performance was that much more impressive. His value to the Celtics has never been higher, or made clearer, than in the 38 minutes he was on the floor that night.

The Celtics' net rating was +12.8 with Thomas in the game. Their offense performed on par with the regular-season Golden State Warriors and their defense was more stout than the regular-season San Antonio Spurs. He scored 33 points with a 32.0 percent usage rate and 70.9 True Shooting percentage, plus six assists and five rebounds for good measure.

But when Thomas wasn't in the game, the Celtics looked like a decrepit D-League squad. They were outscored by 16 points in 10 minutes despite Brad Stevens going out of his way to ensure that starters Jae Crowder, Al Horford, and Avery Bradley were still on the floor. And it cost them the game—Boston lost to Chicago by four.

To create offense, Boston tried posting Horford, who was otherwise fantastic, up against Nikola Mirotic and Bobby Portis, but these possessions dissolved into ugly isolations outside of the paint and decent looks inside that simply didn't fall. All in all, the Celtics weren't able to generate anything productive, and it forced Stevens to try Gerald Green in the second half. That didn't really work, either.

Even though the Celtics had a quality defense with Thomas on the court, the Bulls still went out of their way to attack him throughout the game—whether it be with a Rajon Rondo or Jerian Grant post-up (awful decisions) or pick-and-rolls with Thomas' man screening for Jimmy Butler to force a switch. The Celtics did a good job hedging and recovering out of these tough spots, but Thomas still ended up in uncomfortable positions late in the shot clock when the only option was to switch.

And even though Thomas scored 33 points on 18 shots, the Bulls did a pretty good job putting two defenders on the ball just about every single time he initiated a pick-and-roll. According to Synergy Sports, Thomas finished 23 possessions as a pick-and-roll ball-handler, and the Celtics produced .957 points per possession when he shot, passed, or turned it over.

That's a quality number, and it would've been even higher if Boston knocked down its jumpers after Chicago forced Thomas to give up the ball. The simple adjustment here for the Celtics is just to play their best player even more in Game 2—Thomas is expected to play on Tuesday before going home to be with his family—and beyond, but to ensure even more efficient offense, Thomas' supporting cast needs to knock down the open shots they're gifted when he kicks it out.

Chicago's defensive strategy appears to be gambling on guys like Bradley, Crowder, Marcus Smart, Kelly Olynyk, and Horford to miss open looks. It worked in Game 1, but it's a long series. If Thomas continues to occupy all Chicago's defensive attention when he's on the floor, the Celtics will eventually take advantage by attacking elsewhere.