In the regular season the Celtics scored 107.4 points per 100 possessions while only allowing 96.4. The team’s efficiency differential – offensive efficiency (107.4) minus defensive efficiency (96.4)-of 10.95 was the best mark since the Chicago Bulls differential of 13.00 and 11.61 seen in 1995-96 and 1996-97 respectively. In fact, other than these two Chicago marks, the Celtics mark in 2007-08 was the best since 1973-74 (the first season we can calculate efficiency differential).
Such a performance led me to label this team the best Celtics team in franchise history. Given the 16 titles won in Boston history, I clearly believed (as did many others) that the Celtics would coast to an NBA title.
Boston in the Playoffs
And then the playoffs started. In the post-season the Celtics have scored 105.2 points per 100 possessions while allowing 99.0. In words, Boston’s offense -relative to the regular season – has declined. And their defense has worsened. As a consequence, their efficiency differential in the playoffs is only 6.23. This is still an excellent mark, just not nearly as good as what we saw in the regular season.
So what happened?
For an answer, let’s turn to Wins Produced. Table One reports what the Celtics could have expected in their first 14 playoff games had the player’s performance not changed from the regular season. It also reports what we have actually seen in the post-season.
Table One: The Boston Celtics after the First Two Rounds of the 2008 Playoffs
The expectation going into the playoffs is that the Celtics would easily dispatch Atlanta and the winner of the Cleveland-Washington series. Both Atlanta and Cleveland had negative efficiency differentials in the regular season, and even with Cleveland’s major mid-season trade, one should not have expected the Cavs to contend with a team boasting a 10.95 efficiency differential.
Again, though, this is not the team that Cavs (or Hawks) ended up facing. When we look at the performances of the individual players we can see which players are primarily responsible for Boston’s drop-off. And those players are Paul Pierce, Leon Powe, and Ray Allen. As Table One reveals, these three players account for 75% of the Celtics post-season decline.
The decline of Pierce, Powe, and R. Allen
So what happened to these three players? That question is addressed in Table Two.
Table Two: Pierce, Powe, and R. Allen in the First Two Rounds of the 2008 Playoffs
Table Two reports what each player did – per 48 minutes – in both the regular and post-season. Post-season marks in red are statistics that have declined from what we saw in the regular season. The fact that the table just bleeds suggests that these three players have just gotten worse with respect to everything.
But that’s not quite the case. Some aspects of performance are much worse than others. At the bottom of the table the change in the player’s production is divided into scoring, net possessions, and BLK-AST-PF. For Piece, 52% of the decline in his per 48 minute Win Score can be attributed to declines in factors associated with scoring. For Powe we also see a substantial decline in scoring (46.5%), but an even bigger decline in net possessions (55.6%).
And then there is Ray Allen. Ray Allen seems to be the player people target the most in looking at the Celtics post-season woes. His overall decline, though, is not quite equal to what see from Pierce or Powe. Still, he is playing worse. And from Table Two we see that 90% of his troubles are associated with scoring.
It’s important to note that if Ray Allen returns to form, the Celtics will improve. But not as much as they would if Pierce or Powe returned to what we saw in the regular season. Yes, the hero of the second round game seven and a little known reserve may have to step up even more than the much abused Allen for Boston to return to form.
The Pistons Close the Gap
Does all this mean that the Pistons have closed the gap? In the regular season the Pistons had an efficiency differential of 8.17. In the post-season this differential has declined to 5.10. Yes, the Celtics still boast a better differential even when we compare just the post-season performance of each team.
One should note, though, that the Pistons have faced better competition than Boston. So one could argue that the Pistons have closed the gap. Certainly as a Pistons fan I hope this is the case.
Had the Pistons maintained their regular season performance we would not have to discuss strength of competition. If that were the case the Pistons would have thus far surpassed the Celtics. Why were the Pistons unable to maintain what we saw in the regular season? One answer, as detailed in The Wages of Wins, is that playoff performance tends to be worse than the regular season (due to improved competition). One Piston, though, has decline a bit more than we would expect.
Table Three: The Detroit Pistons after the First Two Rounds of the 2008 Playoffs
As Table Three reveals, virtually all of Detroit’s decline can be attributed to Rasheed Wallace. In the regular season his WP48 [Wins Produced per 48 minutes] was 0.142. In the post-season his mark is only 0.031.
Wallace is not the only one whose performance has changed. Chauncey Billups is also offering less while Tayshaun Prince is now leading the team in Wins Produced. If Wallace and Billups can return to form, and Prince keeps producing, the Pistons might just advance to the NBA Finals. And if that happens, I think the Pistons might just win their fourth NBA title. Or to put it another way, I think the winner of the Celtics-Pistons series should be favored over either the Lakers or Spurs.
Let me close by noting that fans of Boston and Detroit should look forward to a great series. As I noted a few weeks ago, the current edition of each team is the best in each franchise’s history. In sum, this should be real fun (and even more fun if the Pistons win).
– DJ
Our research on the NBA was summarized HERE.
The Technical Notes at wagesofwins.com provides substantially more information on the published research behind Wins Produced and Win Score
Wins Produced, Win Score, and PAWSmin are also discussed in the following posts:
Simple Models of Player Performance
What Wins Produced Says and What It Does Not Say
Introducing PAWSmin — and a Defense of Box Score Statistics
Finally, A Guide to Evaluating Models contains useful hints on how to interpret and evaluate statistical models.
Wages of Wins Journal 
John Davis
May 20, 2008
Go Pistons! Pistons in 6!
Vince Gagliano
May 20, 2008
But if the Celtics were to “easily dispatch” the Hawks and Wiz like they did the regular season, you would have to shorten the time frame; making the expected Wins Produced more equal.
By the way, why would the Celtics choose a three-leaf clover for a logo? Isn’t four more lucky?
Could the team’s struggles in the playoffs show that the accursed nature of the Boston teams of old is returned?
And if the Pistons and Red Wings win the championships in their respective franchises, will the Motor City overtake Beantown as America’s most successful sports city? Say it six times fast.
Leroy Allen
May 20, 2008
The biggest advantage for the Celtics might be homecourt. What are the statistical differences that make up homecourt advantage? Is it general or does it effect specific parts of player performance? Or perhaps the refs are implicated. Any insight would be much appreciated Professor Berri. Thanks.
Josh Lewis
May 21, 2008
Dave,
As with the LeBron v. Kobe argument, many will point out that Boston and Detroit’s efficiency differential was boosted by playing the majority of their games against the atrocious East.
I know you ran some numbers that showed Bron was even better against the West. Have you broken this down for Boston and Detroit?
My gut says that the Lakers are going to thrash the Spurs in no more than 6 while the Pistons/Celtics series goes a tough 7 games. I can’t see either of them being much of a favorite against the Lakers. A pick ’em at best.
The Lakers started pretty average (at least for the West) and have steadily improved while it seems the aged favorites in the East have gone the opposite direction. (Let’s not forget the Pistons dropping 2 to the sub .500 Sixers.)
Just my .02 cents. I’d love to see a little analysis to show if I’m talking out my hindquarters or the numbers back me up.
A-ro
May 21, 2008
The Cavs have overachieved two years in a row in the playoffs. Could it be that having a star scorer who can elevate his game (like James) is a key to playoff success?
MattB
May 21, 2008
I think it’s going to show that this sample is far too small when the C’s dispatch the Pistons in 5 games…
The matchup is far different than the Hawks and Cavs. As we saw last night, the Celtics are perfectly happy to defend half court sets and screens. They haven’t had trouble with that in the post season. It’s the run anad gun teams that were getting out on streaks and causing problems.
As the numbers already suggest, the C’s take this series, and as our eyes saw last night, it will be relatively easy.
Tommy_Grand
May 21, 2008
Is Sam Cassell overpaid? I know he signed for millions, and I doubt he’s contributed many wins this season.
Of course, SC was signed as an insurance policy — against the contingency that Rondo would flame out. Since RR has played great, SC hasn’t been needed much. So, was the insurance too expensive? Or was it worthwhile?
mrparker
May 21, 2008
Paul Pierce has had to play against two of the best small forwards in the first two rounds. WHile wow does not like Josh Smith it loves Josh Childress. He is a great offense player. However, Josh Smith is probably the third best defensive small forward in the league after Paul Pierce and Lebron James. If you combine Josh Smith and Josh Childress into one player(they split the minutes at small forward), in essence Paul Pierce has played against the only other two small forwards in his league when you consider both offensive and defensive prowess. *I used the wins shares method to rank the small forwards.
Without having an answer for Pierce I doubt any team can get past 5 or 6 games against Boston when they have home court.
I am picking the Celtics in 5. Billups should dominate the point guard matchup but after that the Celtics hold a significant advantage at every other position.
Paul Pierce getting going should open things up for everyone else. No team has had an answer for Garnett. For the first time in the post season no team is going to have an answer for pierce.
*****************************
I like the Spurs in 6 in the other series. No team has a legit answer for ginobili. Ginoboli is the quintessential wow .3wp48 player that leads his team’s offense. The way San Antonio is constructed I can’t think of one team that can take them out in less than 7. I’m looking forward to Boston vs. San Antonio with Boston winning the series in 7 games.
Jason
May 21, 2008
Cassell did not sign for “millions” in Boston. They got him for the pro-rated NBA minimum which worked out to less than $500k. The “millions” he’s receiving are from his LAC buyout. In NBA economics, Cassell was essentially free to the Celtics. Yeah, a funny world where a half a million is negligible.
SJ
May 21, 2008
You had me until you brought Pierce into it. I’d argue to death that saving the day with a magnificent Game 7 can overcome statistical declines. If it weren’t for Pierce, we’d be talking about LeBron right now. I’d say Ray Ray is pretty shot these days, but PJ Brown could make up for Powe. As a matter of fact he’s gobbling up most of his minutes.
Detroit plays the type of game that Boston is comfortable. If there was ever a team that Boston could beat on the road, it is the Pistons. They slow it down, they execute, they make it a half court game. The C’s are excellent at half court defense. They won’t have to worry about LeBron wreaking havoc or the Hawks pushing the ball every which way. Combine that with the fact that Chauncey is as hobbled as can be and it’s not good news for the Pistons.
Celtics in 7.
oookay..
May 21, 2008
Really, Paul Pierce declined more than Ray Allen? I mean, he only had to guard LeBron friggin James for seven games in round two, turning him into Prince “LeBrick” James, to quote Skip Bayless. Then he carried the C’s to victory in game seven, while Jesus Shuttlesworth has yet to show up to the playoffs. I’m a Lakers fan, and even I think this is absurd.
mrparker
May 21, 2008
oookay,
Its not like Berri is saying Paul Pierce sucks. He is just reporting what happened.
Andrew G
May 21, 2008
He’s not saying Pierce is playing worse than Allen. He’s saying that he’s playing a lot worse than regular season Pierce.
It just shows the chasm that exists between Pierce and Allen, and just how bad Allen played this year, relative to in-his-prime-Allen.
ktfrek
May 21, 2008
there’s no denying that pierce isn’t playing as well in the post season, but i’m still going with their playoff trend. celts in 7. they manage to pull it off.
Todd
May 21, 2008
So, where’s the stats for tracking down a loose ball while hedging out LeBron at the end of the game? How astonishing that a team’s offense is having a harder time in the playoffs. With the economy in decline, perhaps you economists could work on that instead of trying to tweak basketball boxes into knowledge. Good God.
Matt
May 22, 2008
This guy is nuts. “If you add point and reb, multiply by assists squared, divided by turnovers + the cube root of minutes, it shows that this guy is better than this guy”…..anybody who believes this stuff is just as crazy
mrparker
May 22, 2008
Matt+ Todd,
If its such bull then why bother reading it?
Nick
May 22, 2008
Leon Powe has played 10 mpg in the C’s losses (17 mpg in the wins).
Kevin Garnett has played 40 mpg in those losses.
I also saw that KG’s WS per minute is worse in those losses than it was during the regular season losses (though not by much .269 vs. .299).
Now you need more numbers, but wouldn’t these be the relevant stats to finding out why the C’s are losing?
You know, the stats from their losses.
I just have a hard time believing that a guy who plays 10 mpg is having a much greater detrimental impact than another who’s playing 40 mpg. It’s not impossible but facially difficult to believe.
Jason
May 22, 2008
In the losses, anecdotally, it appears that Powe often subs directly for Garnett. It also appears from the plus-minus in games that the Celtics find similar cumulative deficits in the 10 minutes with Powe that they do in the time with Garnett on the floor.
Take it with a grain of salt. It’s anecdotal based on looking at handful of games and doing no in depth analysis, but it does look like that in losses, the Powe-on-the-floor Celtics fall behind very quickly.