Every week, The New York Times will choose one essential game to watch, highlighting hot teams, winning and losing streaks and statistical intrigue in the N.B.A.

Los Angeles Clippers at San Antonio, Saturday, 9 p.m. Eastern, ESPN

At this point last year, the San Antonio Spurs were in first in the Southwest Division and in second in the Western Conference, at 33-10. That represented something of a worst-case scenario: In the past four seasons, the team has not finished worse than second in the West. (And by the end of last season, the Spurs were back in first.)

Through Saturday’s games, San Antonio was sitting in seventh, at 28-17. But the Spurs often start at a jog before sprinting into the postseason, and they had won eight of their 11 games this month entering Sunday’s matchup with Milwaukee. Much more interesting to Spurs fans than the team’s mildly worrisome (and rapidly improving) record should be the way that the squad is evolving.

The most notable development is the growing importance of forward Kawhi Leonard. Without Leonard, who has missed 18 games this season, the Spurs have gone 9-9. They are better in virtually every important statistical category when Leonard plays, most tellingly defensive efficiency: Entering Sunday, the team had allowed 95 points per 100 possessions with him and 103 without him. The first mark would make the Spurs the best defensive team in the N.B.A.; the second would leave them outside the top 12.