Defense does become better in the playoffs . . .

[sp6r=underrated]

or at least recently it does.

The table below compares and contrasts defensive performance in the regular season and the playoffs during the 2000s. The two metrics used in this comparison are Pace (Possessions Per 48 Minutes) and Offensive Rating (Points Per 100 Possessions).

Sidenote: I wonder if the massive drop-off in offensive effectiveness in the 04 playoffs is partly the reason the NBA decided to make adjustments for how the game was officiated.

http://theresastatforthat.blogspot.com/

The conclusion that should be reached based on the tables is that playoff defense is better relative the regular season and has been becoming increasingly better from the 1980s to the present. I originally thought it was analysts not looking deep enough into the stats. Why has playoff defense improved more as time progressed? I can't really explain it. Any ideas?

Anyone have any theories?

[wiLQ]

The conclusion that should be reached based on the tables is that playoff defense is better relative the regular season and has been becoming increasingly better from the 1980s to the present. I originally thought it was analysts not looking deep enough into the stats. Why has playoff defense improved more as time progressed? I can't really explain it. Any ideas?

Anyone have any theories?

I have no problem with generating theories... but proving them would be a real challenge here ;-)
1) Better adjustments between games because of video equipment, statistical analysis etc.
2) "Defense wins championships" mantra becomes a reason why teams change their approach in the playoffs?
3) I don't know if author included that but... what type of teams usually qualify for playoffs now?
Maybe most of them are simply better at defense than at offense? Especially those fringy ones.
4) Maybe there's a difference in calling fouls between regular season and playoffs?
So it could mean less free throws and less points overall.

[Nivek]

My guess is that #1 plays a big role. After the first couple games, teams would know each other extremely well. They'd probably know each other's play calls, and could pick up changes very quickly based on how the offense sets up. Days of rest may also play a role. In the playoffs there aren't back-to-backs or 4 games in 5 nights sets. They stay in a single location for several days at a time and have a chance to get some rest.

#4 is likely testable -- at least on the question of whether teams shoot fewer free throws. Check fouls per possession would sort of address whether refs are more or less likely to call fouls (doesn't address the subjective stuff like playoff games may be more physical, which could mean that while the refs call the same number of fouls, there could still be a change in the way games are officiated). But, free throw attempts per possession would address the question of whether free throws decline in the playoffs.

[ARISE_CHICKEN]

Familiarity, days off between games, and just straight up more effort (probably related to rest between games) would be my best guess.

[mysticbb]

I would argue that some (maybe even the most part) comes from the fact that the teams are playing against overall better teams. If we would look into the regular season matchups between only playoff teams, we will find that they score less points. I somehow doubt this analysis adjusted for this. For example: In this season the playoff teams scored in average 99.7 points per 48 minutes against all competition, but they only scored 96.2 points per 48 minutes against playoff competition.
The playoff teams are not just better offensively, but also better defensively. In average the playoff team had a 105.2 DRtg in this season.

If we now take the regular season numbers and calculating a minute adjusted average (taking the minutes played in the playoffs so far) for ORtg and DRtg, we are getting 109.0 vs. 104.7, we might expect a overall average of 106.8 in that case. We are now at 105.8 average for the playoffs. And that calculation didn't even take only the games against the playoff competition during the regular season into account. As I mentioned before the scoring is lower in those games also in the regular season.

So, overall I doubt this analysis can say for certain that there is better defense in place. And it is not able to quantify the difference.

Another example: 2004, the minute adjusted average ORtg vs. DRtg (adjusted for playoff minutes played) for the playoffs teams in the regular season was 104.2 vs. 100.0, the expected value would be 102.1. Thus 3.7 points of the drop in ORtg just comes from the fact the playoff teams were better defensive teams. The remaining 3.3 points might be due to better defense in the playoffs, but I guess a part of that can be found in those regular season matchups of the playoff teams.

[Paydro70]

There is at least something to #4: http://www.apbr.org/forum/viewtopic.php?t=253

If the refs are indeed calling fewer fouls in the last decade in particular, that would help explain the shift in the last decade of reduced scoring. Not all of it, though... I'd put the rest just on extra defensive effort (easier to slack on that during the regular season). I'd also join with mysticbb in wondering whether this "regular season" number is based on all regular season games or just playoff teams' games. It's rather easy for me to imagine a lot of good teams not playing their best defense, in particular, against bad squads that can't really punish them.

[NO-KG-AI]

Quality of teams? The worst team you'll play in the playoffs is mediocre, so teams aren't running up huge numbers on bottom feeders.

Effort level, and familiarity are big deals too.

[ElGee]

wiLQ's #1 is testable -- just check to see if ORtg decreases as series unfold.

Otherwise, I think mystic hit the nail on the head here. At first the data looked interesting to me, but it's missing a giant piece: the average defensive ratings of the teams! It's just biased to the offensive perspective right now.

For example, the average DRtg of the playoff teams last years was 105.1. The Drtg in the playoffs was 108.6, and that's without weighting it for teams playing a different number of playoff games.

The best way to do this would be to look at both offensive and defensive strengths and weight the playoff relative to those averages. As of now, the way the numbers are set up are flawed and inconclusive. Interesting idea though...

EDIT: Some of the data also looks off. I have the average pace for last year's PS teams at 92.0 in the RS. Not sure how he got 92.7...

[ElGee]

Also, since pace does slow down, some of the easy baskets from transition might be going away, thus bringing down efficiency. I wonder if ORB% also decreases with pace, indicating a shift in strategy to prevent more transition (and maybe that wasn't present in the 1980s). For last year, at least, the ORB% of the teams (averages) went from 26.4% for the RS to 25.9% for the playoffs.

[statforthat]

I am the author of the post in question. Mystic, your concerns have already been taken into account. The pace and offense rating stats are for the playoff teams only. Therefore, the tables do show a valid comparison of regular season defense to playoff defense.

[statforthat]

Hi Elgee

You said: "Otherwise, I think mystic hit the nail on the head here. At first the data looked interesting to me, but it's missing a giant piece: the average defensive ratings of the teams! It's just biased to the offensive perspective right now."

I say: I could have used offensive or defensive rating, they are two sides of the same coin. In doing my research, I saw that the difference between the playoff teams' and non-playoff teams' regular season offensive rating was about the same as the difference between their defensive ratings. In the post-season the playoff teams are the universe/population, therefore, their weighted average offensive rating is exactly the same as their defensive rating. However, I do concede that my measure for offensive rating of the playoff teams is not completely accurate, but it is an excellent approximation. I don't know a better way to measure it; if you just use their regular season offensive rating against playoff teams you will only use 21 to 30 of each playoff teams' regular season games as a sample. The sample size is too small for a season that has 82 games.

After saying all that, you were right about my 2010 playoff teams' pace; my number was off. So this conversation is almost moot; with an error like that you just can't trust the numbers. I will be going back to check all the numbers again. However, I must say that your critique of my assumptions and methods is incorrect. Thanks for the honest feedback.

[mysticbb]

I am the author of the post in question. Mystic, your concerns have already been taken into account. The pace and offense rating stats are for the playoff teams only. Therefore, the tables do show a valid comparison of regular season defense to playoff defense.

Well, in that case I would like to see your raw data, because using basketball-reference.com numbers gives me different numbers than yours. In both of my examples you get a BETTER offensive rating for the playoff teams against other playoff teams, while I get worse numbers. My result is something we can expect, yours is quite the opposite.

In addition to that you wrote as an answer to Elgee that ORtg and DRtg would be the same. For your test it is not the case, because you are comparing an sample with "only playoff teams in the regular season" with a sample "only games in the playoffs", the teams played different minutes in playoffs, thus your weighted values from the regular season will give you most likely a different ORtg and DRtg. The regular season sample shows a difference in ORtg and DRtg for those teams. And I'm still not convinced that you extracted the games between playoff teams only from the rest for your regular season numbers. The expected value in the playoffs would be rather the average of the ORtg and DRtg of the playoff teams. When a team with a 106 ORtg plays a team with a 100 DRtg, we can expect the offensive team to be more or less at 103 ORtg in the end, our expectation shouldn't be 106.

The teams are playing better overall teams in average in the playoffs, thus a drop is expected just due to better opponents. As Paydro made the point clearer: Against better opponents in the regular season, the teams might be willing to also play more motivated on defense as against the non-playoff teams.

[statforthat]

I am the author of the post in question. Mystic, your concerns have already been taken into account. The pace and offense rating stats are for the playoff teams only. Therefore, the tables do show a valid comparison of regular season defense to playoff defense.

Well, in that case I would like to see your raw data, because using basketball-reference.com numbers gives me different numbers than yours. In both of my examples you get a BETTER offensive rating for the playoff teams against other playoff teams, while I get worse numbers. My result is something we can expect, yours is quite the opposite.

My table clearly shows that offensive rating gets better in playoffs 7 times in the 80s and 90s, but in 25 other years the time offensive rating gets worse. In the 80s it stayed the same at 108.4 and it dropped during the 90s and 2000s. Are your numbers comparing team by team or are aggregating and weighted averaging the playoff teams' stats. If you are going team by team, you will have to use your method of averaging one teams off rating with the opponents def rating. I'm judging the playoffs in aggregate, and of course, weighted by the number playoff games each team played.

In addition to that you wrote as an answer to Elgee that ORtg and DRtg would be the same. For your test it is not the case, because you are comparing an sample with "only playoff teams in the regular season" with a sample "only games in the playoffs", the teams played different minutes in playoffs, thus your weighted values from the regular season will give you most likely a different ORtg and DRtg. The regular season sample shows a difference in ORtg and DRtg for those teams. And I'm still not convinced that you extracted the games between playoff teams only from the rest for your regular season numbers. The expected value in the playoffs would be rather the average of the ORtg and DRtg of the playoff teams. When a team with a 106 ORtg plays a team with a 100 DRtg, we can expect the offensive team to be more or less at 103 ORtg in the end, our expectation shouldn't be 106.

I'll address the end of the quote first. If you mean that you're going game by game in the playoffs to compare expected off rating to actual off rating, then I agree with you. However, that is a bit tedious and I would like to see the results of such a study. It may be slightly more precise, but I don't see it being different enough from my results to justify the extra work. I said that the average of the playoff teams' offensive and defensive rating in the playoffs would be the same, as they are the entire universe/population. The off rating and def rating of the entire league in the regular season are the same, is it not? I never said I extracted the games between playoff teams only from the rest of my regular season numbers. I said that I only used the playoff teams' [b]entire[b] regular season numbers; all 82 games for only the playoff teams. Using the reg season numbers of only the games between the playoff teams would be problematic; that would be only 21 to 30 of each playoff team's 82 games which is not a large enough sample. Even using my method of using all the regular season games of each playoff team in the regular season pace and off rating numbers is flawed, but both of the aforementioned methods are flawed.

The teams are playing better overall teams in average in the playoffs, thus a drop is expected just due to better opponents. As Paydro made the point clearer: Against better opponents in the regular season, the teams might be willing to also play more motivated on defense as against the non-playoff teams.[/quote

]

I agree; motivation makes defense better in the playoffs. That was part of the premise of my article.

[ElGee]

Hi Elgee

You said: "Otherwise, I think mystic hit the nail on the head here. At first the data looked interesting to me, but it's missing a giant piece: the average defensive ratings of the teams! It's just biased to the offensive perspective right now."

I say: I could have used offensive or defensive rating, they are two sides of the same coin.

Just to clarify something: are you saying that the RS numbers in the table are JUST playoff teams playing against other playoff teams?

[wiLQ]

I am the author of the post in question. Mystic, your concerns have already been taken into account. The pace and offense rating stats are for the playoff teams only. Therefore, the tables do show a valid comparison of regular season defense to playoff defense.

Well, in that case I would like to see your raw data, because using basketball-reference.com numbers gives me different numbers than yours.

Yeah, thanks for the reminder of a lesson #1: check numbers before creating any theories.
There's something wrong with those tables. For example, let's take this one:
http://3.bp.blogspot.com/-5EEK5PvwrwM/TdSBb6QpiBI/AAAAAAAAATc/m0J_-wB3V8E/s1600/PlayoffDefense2000s.png
Offensive Rating for all 16 playoff teams last regular season was 109,8?
According to http://www.basketball-reference.com/ there were only 7 teams better than that... and one of them stayed home. On the other hand, Pacers were well below average!

BTW, thanks to this topic I've stumbled into something IMHO interesting: in 1990s and 1980s playoff teams in regular season were better at offense than at defense [comparing to league average] but in a last decade it was the opposite. Incidentally it would also be the anwer for a question which has started this topic.

[qianlong]

Without reviewing the data it seems logical to me.
Generally defensive teams go deep in the playoff, accordingly they play more, and have more weight on the average.
The reason for why it has changed overtime seems to be the one emphasized by wiLQ: in the previous decades offensive teams were going deep, in the present defensive teams play more.
Waiting for clarifing info on the tables.