A microcosm of defensive inconsistency

[Editor's Note: It turns out Trade Deadline day will be a special one for SSR after all.  No, we haven't flipped Luke Walton's contract for an All-Star, but  we do have the opportunity to introduce the newest member of the SSR team.  On Monday, I decided to feature the content of our members, so I went searching for top quality work in the fanpost section, looking at posts that garnered a fair number of recs.  I quickly found a nice analytical feature with strong presentation written by ActuarialSound that fit the bill and put it on the front page.  Then I looked for more posts.  I found another one ... written by ActuarialSound, and then another one ... written by ActuarialSound.  I already knew the guy was doing some high quality work, but I had no idea how much.  All told, he's written 5 heavily analytical posts in three weeks, and every single one has been well received by the SSR masses.  

Giving him the opportunity to write for the site in an official capacity was an easy decision, and we are delighted that he has gratefully accepted the invitation to join our team.  Nothing makes me happier than promoting new talent from within the community, and for that reason, we have every bit as much reason to be excited as the fans of teams bringing in new players today.  Without further ado, the editorial debut of SSR's newest author, ActuariallySound.]

Last nights victory over the Portland Trailblazers feels like something from Ripley's Believe-It-Or-Not Museum.  This Lakers team has been successful by dominating the paint with its three man front-line while Kobe provides additional scoring from the mid post.  They do well to draw fouls and avoid fouling at the other end which gives them the 4th best free-throw rate differential in the league.  Their biggest downfall is their poor perimeter shooting, typically led by Ron Artest with an assist from Derek Fisher.  All those items got flipped upside down last night as the Lakers were not dominant inside for most of the night, had less than half the free throw attempts the Blazers did prior to the end of game intentional fouling, while Artest and Fisher combined to hit 7 of 10 three point attempts. The offensive end was a complete 180-degree turn from the regular season trend.  All of these items could make for a very interesting and long discussion.  However, I actually find the 4th quarter defensive performance to be even more fascinating, as it was a near perfect microcosm of the season so far.

At the start of the 4th quarter the Lakers found themselves down two points.  Over the next six minutes and twelve seconds the Blazers would score 14 points in only 9 possessions for an offensive efficiency of 156.  The Lakers soon found themselves down 10 with just under six minutes left.  But then the game changed and the Lakers gave up only two more points the rest of the quarter holding the Blazers to an offensive rating of only 25 during the stretch.  They were able to force overtime and then pull out the much needed victory.  So the big question is, "what changed between the first six minutes and the last six minutes defensively?" The answer...

The Line-up!

The line-up during the first six minutes was made up Blake, Brown, Bynum, Odom, and Bryant for the most part (Artest did start the first couple possessions of the quarter in place of Kobe).  The line-up during the second six minutes was the Lakers typical closing unit of Fisher, Bryant, Artest, Odom, and Gasol.  An interesting trend has begun to develop in regards to the defensive efficiencies from various line-ups that the Lakers utilize. Here is a table showing the offensive, defensive, and net efficiencies of the Lakers line-ups with at least 40 minutes of playing time together:

The Lakers have had some very good defensive units (below 100) and some very poor ones (above 110).  What are most interesting are the similarities between all of the really good defenses and those of the really poor ones.  They aren't easy to quickly distinguish from the table so let me group the line-ups into the following three groups: Line-ups where the perimeter players are starters (Fisher/Bryant/Artest), Line-ups where the perimeter players are bench players (Blake/Brown/Barnes or Walton), and Line-ups that are a mixture of the starters and bench players.  The following graph shows those same 13 line-ups now color coded into the three aforementioned groups.

Now isn't that interesting.  All four of the Lakers line-ups that have poor defensive efficiencies have a mixture of starters and bench players at the three perimeter positions (the white bars) while all of the line-ups that have good or great defensive efficiencies are either strictly starters (purple) or bench players (gold) and it really doesn't matter which.  If we consolidate the results of all these individual line-ups and into three groups and graph the offensive and defensive efficiencies the results look like this:

They say a picture paints a thousand words but that graph paints even more than that as there is so much we can take away from it.  Before continuing to discuss the defense, a quick observation about the offense.  The offensive efficiencies from the all starters group and mixed group are almost identical at around 115.  Each of the line-ups in the mixed group does have Kobe Bryant as part of it so essentially the only players changing are the switching of Fisher for Blake and Artest for either Brown, Walton, or Barnes.  It should not be much of a surprise then that these efficiencies are nearly identical as neither of those substitutions really improves or hurt the offense.  On the other hand, when Kobe Bryant leaves the game and we look at the all bench unit you can see the offensive efficiency drop down to 107.2 (a decrease of 8 points) despite that unit going against inferior players most of the time. I think that really shows the value that Kobe brings on the offensive end, both scoring and creating opportunities for others.

Now back to defense.... The starting unit does a very solid job defensively with a 102.3 rating, especially when you consider that they go against the oppositions best players most of the time.  The bench also does a wonderful job holding the opposition to only 95.7 points per 100 possessions.  While the bench is holding the opposition to a lower output than the starters, they are going against inferior players most often so a straight comparison isn't really fair. All that being said, both homogeneous groups are producing great defensive numbers. The only issue defensively is when the starters are mixed with the bench players.

Looking back to last night, the unit that gave up 14 points in 9 possessions to start the quarter was none other than a mixed perimeter unit (Blake, Brown, and Bryant) and the unit that held Portland to only 2 points the following 8 possessions was none other than an all starters perimeter unit. So that 4th quarter was indeed a microcosm of the defense the Lakers have seen throughout the year.  The next question to ask is "why?'" Why is it that the Lakers defense suffers so much when the Lakers mix personnel on the perimeter?

In my opinion, the reason is that the Lakers don't play one defensive system but instead two.  When the starters are in the game the Lakers defensive scheme is to switch everything screen on the perimeter and funnel everyone to the big front line of defense.  However, when the bench is in the game the defense changes dramatically on the perimeter as they typically fight through all the screens and try to stay in front of their man. I don't know which is the better system and judging by the results above both seem to be working well. The problem is that when you start mixing the bench players with the starters (especially Kobe) you have a mixture of guys who want to switch screens and those that want to fight through them. Any lack of communication or hesitation on deciding whether to switch or not leads to unguarded players and open shots for the opposition. 

Most teams do not have this issue as the defensive system is the same for everyone and they simply rotate players in and out.  The Lakers are probably the only team in the league that plays two drastically different systems depending on if the starters or the bench is in the game.

In my previous fan post here, I discussed how in the playoffs the Lakers play their starters heavy minutes and cut back on the bench.  This could bode very well for the Lakers' defensive performance, because it seems clear that the defensive chemistry of the starting back court leads to improved defensive performance.  In fact, it may behoove the coaches to play Fisher, Bryant, and Artest for 38 to 40 minutes per game and then pull all three out and put in the combination of Blake, Brown, and Barnes or Walton the rest of the time.  As long as the groups are not a mixture of starters and bench players the Lakers will probably be a much better defensive team than they have shown so far this year, as they will be avoiding the combinations, both of players and of styles, that truly cost them games.