After 14 games, the Celtics  are 10-4, comfortably in first place in their division and just one game behind the league leaders (Atlanta , Orlando  and Phoenix , who all beat the Celtics  in the last 10 days). The Celtics also have the NBA’s best point differential at +8.8, and point differential is a more reliable indicator than record.
Despite all that, something seems wrong with the Celtics, who needed overtime to get past a dreadful Knicks  team and have lost three of their last five, with all three losses coming against the aforementioned teams with better records. So, what gives?
First, their record and point differential are skewed from the first five games of the season, when the C’s ran roughshod over the league and people started seriously considering 72 wins. The Celtics won the next game, 92-90, against Minnesota , but that’s when their play started to slip.
Point differential: +21.6
Points for: 101.4
Points against: 79.8
Point differential: +1.7
Point for: 96.7
Points against: 95
By far the biggest slip in terms of individual offensive numbers belongs to Rasheed Wallace , who made 15 of his first 33 3-point attempts through the first five games and has been 7-for-48 from beyond the arc ever since. Wallace has acknowledged that he’s in a slump, but the general consensus is that he is taking good shots and they’re just not falling for him. That happens. On the positive side, it has not affected Wallace’s defense.
Ray Allen  has been a similar 3-point shooting slump, although not nearly as pronounced. Through five games, Allen was 9-for-21. He is 7-for-29 in the last nine. Despite shooting 32 percent from 3-point range, Allen has continued to be a productive offensive player by shooting 57 percent on his 2-point shots (60-for-106).
Digging a little bit deeper, 82games.com  has Allen as the Celtics’ most productive player in terms of on-court plus/minus with Wallace second, so while their shooting slumps may account for the Celtics’ drop offensively, the real issue is a defense that went from giving up less than 80 points a night (a number that is skewed by holding Charlotte to 59 points) to one that is surrendering 95.
After we plow through the numbers on 82games.com, a few things stand out.
The C’s defense on jump shots is worse  than last year  (.433, 48.1 points per game vs. .417, 43.4 points per game) and they are also struggling defending teams at the end of the shot clock compared to last season (.491 compared to .447). This brings up something Doc Rivers  said last week:
“Some of our defensive sets have been very good, and then with five seconds left on the clock the guy dribbling the ball gets all the way to the basket and that’s not just the guy guarding the ball.”
That speaks to effort, fatigue or just plain understanding the defensive system. It’s probably safe to rule out effort with this group, and “understanding the system” should work itself out in time, but it does explain Rivers saying that the team was “making stuff up” after the Orlando loss. That leaves fatigue, and it’s worth noting that the Celtics’ biggest wins during this stretch ‘ Utah  and Golden State  ‘ came after multiple days off.
That, in a nutshell, is what makes people wary about the Celtics come playoff time. The good news is that we are a long way from April, and most teams would love to struggle out of the gate at 10-4. To be sure, there are other issues, particularly a lack of offensive rebounding and fewer trips to the free throw line, but age will continue to be the dominant theme from here on out.