Last 5 games: Problem is Offense, not Defense

A stat we've been hearing a lot lately is that the Rockets have given up 100+ points to five straight opponents. Apparently, no JVG team has ever done that. In the Chronicle, defense seems to be what the team is stressing most.

Quotes from Chronicle:

Let's look at the numbers in a little more detail:

Code:

               [B]Opponent                 What we did against them[/B]
Date   | Tm     OffEff DefEff |  Poss/2   OppPts  TmPts  DefEff OffEff
----------------------------------------------------------------------
--     | LgAvg  106.2  106.2  |  89.5     --      --     99.8   105.1
----------------------------------------------------------------------
12/9   | @WAS   111.3  111.9  |  95.9     109     114    113.6  118.8 
12/12  | LAL    109.6  106.6  |  96.2     102     94     105.6  97.7
12/14  | @GSW   109.9  109.5  |  102.0    109     107    106.8  104.9
12/15  | @LAL   109.6  106.6  |  110.1    112     101    101.8  91.8
12/17  | @LAC   105.4  108.2  |  90.7     103     108    113.5  119.0
----------------------------------------------------------------------
Total  |        109.2  108.6  |  99.0     107.0   104.8  108.0  105.8
----------------------------------------------------------------------
Wins   |        108.4  110.1  |  93.3     106.0   111.0  113.6  119.0
Losses |        109.7  107.6  |  102.9    107.7   100.7  104.7  97.8

I've included data for the past 5 games. Some parts of the chart might need explanation.
OffEff: Offensive Efficiency, roughly points scored per 100 possessions
DefEff: Defensive Efficiency, roughly points allowed per 100 possessions
Poss/2: an estimate for the number of possessions in a game, equalized between teams (more specifically, average of offensive possessions and defensive possessions)

League wide, on average teams score around 106.2 points per 100 possessions. More specifically, our last 5 opponents on average score about 109.2 pts/100poss and give up around 108.6 pts/100poss. In other words, we can say that they have been pretty good offensive teams, and not very good defensive teams. That's actually an accurate description of each of the last 5 teams we've faced.

Furthermore, this season the Rockets are scoring about 105.1 pts/100poss and allowing only 99.8 pts/100 poss -- we're a mediocre offensive team but a very good (arguably the best) defensive team.

Now, take a look at what we've done against the last 5 opponents. Specifically, let's focus on what we did in the wins and what we did in the losses.

In the wins, we beat Washington and the Clippers. We gave up 113.6 pts/100poss against those two teams, which is terrible. In particular, against the Clippers we gave up far too many points considering they aren't a particularly good offensive team. But the reason we won those games is because we took advantage of their poor defense and scored a lot. We scored 119 pts/100 poss -- far eclipsing our season average and even the average those teams usually give up (110.1). In short, our offense won those games.

Now take a look at the losses. Considering all the focus the Rockets are putting on their D, you'd think it's our defense that lost us those games. Not so. Those 3 teams (Lakers twice, and the Warriors) are all very good offensive teams, scoring close to 110 points/100poss on the season. We actually gave up only 104.7 pts/100poss against them, which is even below the league average. I wouldn't call that bad defense, and in fact it's far better defense than we played in our two wins. Sure, we gave up 107.7 ppg in these losses, but they also had a ton of possessions (combination of high pace and the double overtime game against the Lakers). No, the real problem was our offense. While we scored an amazing 119 pts/100poss in the wins, in the losses we only managed 97.8 pts/100poss. And that's against teams that aren't very good defensively (allowing 107.6 points/100poss). How bad is that 97.8 figure? Consider that the worst offensive team (by far) are the Bobcats and they score about 98.9 pts/100poss. It's bad.

So, in my view if you want to look at the real key to our success (or lack thereof) the last week or two, look at the offense and not the defense. In particular, you'll find that we shot far better from 3 and had far less turnovers in our two wins.

 

I don't expect our offense to be as good as our defense. That's just not the kind of team we are. But in our losses, I thought our defense was more than decent overall against some very good offensive teams. I attribute the points we gave up more to the high number of possessions -- and possession count has little to do with defense in my view. Our defense was bad in the wins, granted, but our offense made up for it. It looks to me that the barometer for our success in these last 5 games was offensive, not defensive, efficiency.

 

It doesn't ... not by the way I'm defining possession. Offensive rebounds extend a possession.

That may or may not be true. For instance, if a team is insanely good at getting steals, they may shorten the other's team's average possession time but give up very few points per possession. That's why, ultimately, I consider points per possession a better way of evaluating offenses (or defenses).

 

It's all from the current date. You seem to be implying that data from points A to point B is a better indicator of a team's state at point B than data from points A to C, where B lies somewhere in between. I don't think that's necessarily true.

 

The offense has been very good in the wins. But in the losses, it's been terrible (and that's where the turnovers killed us, among other things). We averaged just over 100 in the losses, but there were also 102.9 possession per game in those losses. That's a very poor conversion rate -- i.e. bad offense.

 

It may or may not be. I don't think a good defense is necessarily a defense that plays slow, if that's what you're asking. If the defensive strategy is to play at a particular pace, the reason for that isn't to minimize the total number of points allowed so much as it is to minimize the points given up per possession.

Here's the reasoning for that. In a game, both teams will roughly get the same number of possessions, regardless of the pace (possessions/minute). If a particular team's defensive goal was simply to minimize the total number of points allowed, then they might play stall-ball on the offensive end and on each possession try to force the other team to use up as much shot clock as possible. That means they don't attack the offensive boards, they don't go for steals, and they all go for the defensive board. Does that make up the best defensive team they can be? Perhaps, but not necessarily. Maybe they're small inside and that causes them to have to foul a lot. Maybe they have great athletes in the wing capable of forcing a lot of turnovers, but that strength is never utilized. Let's say that at this very slow pace, they allow only 85 ppg and 101 points per 100 possessions (which is very good and would put them amongst the league leaders). That means they need to score more than 85 ppg 101 points per 100 possessions to give themselves a good chance to win.

Now, let's say that if the team played a little faster and utilized more traps in their defense to create turnovers and transition opportunities they could actually improve that defensive efficiency a little, while also increasing the pace. Hypothetically, they may now give up 90 points a game, but only 100 points per 100 possessions. Are they a worse defensive team? I'd say not at all. In fact, they're better because they only have to score better than 100 points per 100 possession, while before they needed to score more than 101 points per 100 possessions. Not to mention that their new defensive approach has benefits on the offensive end, because they get more transition opportunities. Essentially, their defense is now putting less stress on their offense for them to come out on top compared to before, even though they may be giving up 5 more points a game. To me, that makes them a better defensive team.

 

I don't have the same intuition as you.

For example, suppose it was the very first game of the year (or very, very early), and you let the Lakers score 100 points/100poss. Suppose in the next 20 games, the Lakers score 110 points/100poss. Based on that, I would say we probably did a good job on the Lakers in that first game. But you're saying that intuitively you should only take into account games up to that point (which may only be that game), and the conclusion would be that we did an average job on them.

More generally, how good a team is at a particular point in time is reflected not only by their performance in the near past but also their performance in the near future. And my intuition doesn't tell me to favor one any more than the other. That said, a more rigorous way of determining how good a team was on a particular date might be to take an average of their game by game performances weighted by the time period away from the date (either backwards or forwards) and also opponent strength. Some sort of regression would have to be used. It would be pretty complicated, and I doubt very much it would have a significant enough impact on those team averages to make it worth while.

 

If you look at the total for all the games, yes. As I said, we played terrible defense in the wins, but made up for it with very good offense.

But if you focus on the losses, you'll find that our defense was pretty good (considering how good the other teams were offensively), while the offense just downright stunk (even though the other teams aren't good defensively).

In other words, we won when our offense was really good, and we lost when our offense was terrible. We won when our defense stunk, and we lost when our defense was decent. Based on that, wouldn't you conclude that its our offense, not the defense, that we should be more focused on?

In a larger sample it might even itself out (or maybe not, our team was dead tired and totally out of sorts in that second overtime). But since it's only a 5 minute period, which amounts to only 9 possessions, that in itself doesn't skew the final results any more than it should to reflect how terrible we were offensively at the end of the game.

I'd say that our defense in the losses was just fine. We gave up a lot of points because of the high pace, which was in large part due to our terrible ballhandling and high number of turnovers. That's more of an offensive problem than defensive problem, and its something that can largely be attributed to not having McGrady.