The Celtics are now 4-7. On Saturday morning – before the Celtics lost to the Pacers (Boston’s fourth consecutive loss) – Chris Mannix of Sports Illustrated wrote the following.
Are the Celtics old? Of course.
Is that why they are 4-6? Absolutely not.
A reading of the Mannix article reveals that he does think age is playing a role in Boston. But he also thinks more is going on.
I am not sure I entirely agree with what Mannix had to say. And my disagreement primarily comes from the fact Mannix isn’t all that specific as to the nature Boston’s problem. He does note that a team that is 4-7 needs better players. But before Boston starts finding better players, we might want to figure out which players are responsible for what we have seen so far this season. As is often the case, let’s look at some numbers.
The Celtics then and now
Let’s start with the big picture. The Celtics won 56 games in 2010-11. The team’s efficiency differential – offensive efficiency minus defensive efficiency – was 5.8. This mark ranked 6th in the NBA. This season the Celtics have a differential of -2.4, which ranked 20th in the league. Such a mark is consistent with a team that would win 35 games across an 82 game season. So the Celtics – relative to last year – have lost about 20 wins.
At this point, the big picture numbers tell us what everyone – including Mannix — has seen. The Celtics are not as good as they were last year.
When we move from efficiency differential to each player’s productivity, we can identify who is specifically responsible for Boston’s decline.
Last year the Celtics received 46.7 wins from Ray Allen, Rajon Rondo, Paul Pierce, and Kevin Garnett. And the team received 10.4 wins from everyone outside this quartet.
Now let’s look at the Celtics after 11 games:
So far, Ray Allen and Rajon Rondo are still producing. And everyone else – outside the team’s four superstars – is on pace to produce 7.6 wins (across an 82 game season). So it doesn’t appear that Allen, Rondo, or everyone else is the problem.
Obviously that allows us to identify the problem. Kevin Garnett has only produced 0.5 wins across the first 11 games. At this pace – if this were a full 82 game season – he would produce only 3.8 wins across a complete season. In other words, KG is on pace to produced 6.6 fewer wins (again, across a full 82 game season).
Why is KG slipping? If we focus on scoring (see KG’s career per 48 minute numbers at NBA Geek) we don’t see too big of a drop-off (per 48 minutes KG’s scoring has dropped from 22.9 to 20.7). The drop-off we do see with respect to scoring, though, is not really about shot attempts. Garnett is still shooting. Unfortunately, relative to last year, these shots are not going in the basket as often. In addition, KG is not rebounding as well. These two issues have caused KG to go from being the above average player he has always been to a below average performer thus far in 2011-12.
Below average also describes Paul Pierce. Relative to last year, Pierce’s rebounding and assists are up. And his personal fouls are down. But his turnovers are up and his blocked shots are down. These changes, though, are not the big story. Thus far this season, Pierce has an effective field goal percentage (or adjusted field goal percentage) of 45.7%. Last season his mark was 55.1%. It is this decline that essentially has caused Pierce’s Wins Produced – again, across 82 games – to fall from 11.7 in 2010-11 to a 2.7 pace for 2011-12.
If we put the decline we see with respect to Pierce and Garnett together, we see that these two players are responsible for a drop-off of 15.7 wins across a full season. Again, the team has declined by about 20 wins across an 82 game season. And about 75% of that decline is linked to two players who happened to be 35 (KG) and 34 (Pierce) years of age. So that suggests – contrary to what Mannix said – that age might be a problem.
From Stumbling on Wins we learn that basketball players
- tend to peak around their mid-20s
- tend to decline slowly in their latter-twenties
- tend to decline at a more accelerated pace in their thirties
Those tendencies are just that, tendencies. We do not know how each specific player will age. So we should not be shocked that Ray Allen – who is 36 – still seems productive. But we do know that at some point (and this is true for Allen), age will take its toll. At some point, all the aging stars on the Celtics will stop producing.
Has that time truly come for KG and Pierce? After 11 games it looks that way. But 11 games is still a small sample. It’s very possible for KG and Pierce to comeback this year.
So far in 2010-11, it is the decline in KG and Pierce’s performance that is driving what we see in Boston. And until these two players start producing (still possible) or the Celtics find that kind of production elsewhere (perhaps less likely during the season), Boston fans are going to be disappointed. But at least now, they can see who is responsible for their disappointment.