The Boston Celtics lost their fourth straight game Sunday when they allowed the San Antonio Spurs to hand them a 115-96 beatdown in their own floor.

After the game, Celtics' head coach Brad Stevens addressed the team's struggles, saying that he doesn't want to rely on whether their offense is clicking or not.

Brad Stevens is probably talking about Boston's defensive struggles as of late. In their last seven games, they have allowed their opponents to score at least 114 points, the longest such streak over the last 50 seasons. They are 2-5 in that stretch, three of those losses coming against non-playoff teams.

Against the Spurs, Boston's defense was once again a non-factor, especially down the painted area where All-Star forward LaMarcus Aldridge did his damage. He basically torched Boston, finishing with 48 points on 20-of-31 shooting. Aldridge only attempted (and made) one three-pointer.

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As for the Celtics' offense, they were not able to go head-to-head with the Spurs, as none of their players even reached 15 points. Their All-Star guard Kyrie Irving finished with 11 points, but he shot the ball poorly and made only five in 17 attempts.

Throughout the history of the NBA, Celtics' championship teams have always found success by playing tenacious defense. From the Bill Russell era to the Larry Bird years, and even to the Pierce-KG-Allen run, that has been the case. They were all great defensive teams. If Boston is determined to win the title this season, they will need to work on that aspect of their game.