Fun Graphs

[mmmmm]

Great stuff, Vermonter!

Here are a few more graphs that are fairly interesting that I believe help illustrate the 'big change' in the offense the last couple of years. 

This first one plots the percentages of shots at various ranges (as a percentage of total shots) each year.  I also added ORtg, ORB%, eFG% and XeFG%.  XeFG% is the 'eXpected eFG%' if we had the same shot location distribution as league average.



The thing that should jump out at you is the nasty upward turn of the purple line.

What that is, is the share of our FG attempts that were 'long twos' --- notoriously the least efficient way to score points.   As you can see in the chart, the increase in the share of 'long twos' vampirically sucked away from the share of shots taken 'At Rim', 'Short' and even from '3PT'.

The 'long 2' trend and decline in 3PT and 'short' started together and this last year the bottom fell out on 'at rim' shots (we had no inside post players after Wilcox got injured).   And that's what turned a downward trend in ORtg into a steep dive.

The ORB% has also trended down, but that started earlier and is less dramatic a trend line.  But it does generally track the change in shot locations so is almost certainly related.  Partly as a result - guys not playing close to the hoop on offense to be in position to grab ORBs - but also probably partly causal - few ORB grabs resulting in 'At rim' put-backs.

Throughout all of this, it is notable that we continually out-shot our XeFG% by about 2%.  That's a significant gap and a testament to the talent of our team's shooters.  Note how that gap started immediately with the arrival of KG & Ray.  But being great shooters eventually is not enough if you are taking lower efficiency shots.

Shots 'At Rim' and '3PT' shots tend to be 'high efficiency' shots - the former because they tend to be completed at a high rate (60-70%) and the latter because of the extra points returned.  'At rim' also tend to bring home more FT/FGA than other shots as well.

So I thought it useful to roll-up 'at rim' and '3pt' shot shares together.  Here is the trend line of the percentage share of Celtic shot attempts that were either 'At Rim' or '3PT', along with the Offensive Efficiency Rating:



Finally, here is the scatter plot of those two:



Now, that's not a perfect correlation, but it looks reasonably strong for just 6 data points.   I suspect if we gathered more data points we'd get a pretty solid correlation.

I think that these trends have been basically acknowledged by the types of moves Danny has made this year.  Actually, I think it started last year with bringing in Wilcox and the hope that Green and JO would be able to help improve the 'At Rim' scoring - but obviously we lost all three to injury so there is no way to know if that would have helped.

This year, we have Wilcox and Green back, obviously, and Danny drafted Sullinger - who is potentially an extremely efficient low-post scorer.  On top of that, while we lost Ray, we strengthened up our overall 3PT shooting significantly with the additions of Lee, Terry and Green.  None of those guys are the same shooter Ray Allen is, but their are more _of_ them.  Together with Pierce & Bradley, we should be able to have at least 2 legitimate 3PT threats on the floor at all times.

So those things should help push the share of 3PT shots back up and the share of 'Long 2s' back down.

If we can assume (I know, I know) that our DRtg will continue to be one of the tops in the league so long as KG is breathing, these improvements on offense should help pump our ORtg back up, leading to that all-important Net Rating that we know correlates so well with winning.

[Fan from VT]

Great stuff, Vermonter!

Here are a few more graphs that are fairly interesting that I believe help illustrate the 'big change' in the offense the last couple of years. 

This first one plots the percentages of shots at various ranges (as a percentage of total shots) each year.  I also added ORtg, ORB%, eFG% and XeFG%.  XeFG% is the 'eXpected eFG%' if we had the same shot location distribution as league average.



The thing that should jump out at you is the nasty upward turn of the purple line.

What that is, is the share of our FG attempts that were 'long twos' --- notoriously the least efficient way to score points.   As you can see in the chart, the increase in the share of 'long twos' vampirically sucked away from the share of shots taken 'At Rim', 'Short' and even from '3PT'.

The 'long 2' trend and decline in 3PT and 'short' started together and this last year the bottom fell out on 'at rim' shots (we had no inside post players after Wilcox got injured).   And that's what turned a downward trend in ORtg into a steep dive.

The ORB% has also trended down, but that started earlier and is less dramatic a trend line.  But it does generally track the change in shot locations so is almost certainly related.  Partly as a result - guys not playing close to the hoop on offense to be in position to grab ORBs - but also probably partly causal - few ORB grabs resulting in 'At rim' put-backs.

Throughout all of this, it is notable that we continually out-shot our XeFG% by about 2%.  That's a significant gap and a testament to the talent of our team's shooters.  Note how that gap started immediately with the arrival of KG & Ray.  But being great shooters eventually is not enough if you are taking lower efficiency shots.

Shots 'At Rim' and '3PT' shots tend to be 'high efficiency' shots - the former because they tend to be completed at a high rate (60-70%) and the latter because of the extra points returned.  'At rim' also tend to bring home more FT/FGA than other shots as well.

So I thought it useful to roll-up 'at rim' and '3pt' shot shares together.  Here is the trend line of the percentage share of Celtic shot attempts that were either 'At Rim' or '3PT', along with the Offensive Efficiency Rating:



Finally, here is the scatter plot of those two:



Now, that's not a perfect correlation, but it looks reasonably strong for just 6 data points.   I suspect if we gathered more data points we'd get a pretty solid correlation.

I think that these trends have been basically acknowledged by the types of moves Danny has made this year.  Actually, I think it started last year with bringing in Wilcox and the hope that Green and JO would be able to help improve the 'At Rim' scoring - but obviously we lost all three to injury so there is no way to know if that would have helped.

This year, we have Wilcox and Green back, obviously, and Danny drafted Sullinger - who is potentially an extremely efficient low-post scorer.  On top of that, while we lost Ray, we strengthened up our overall 3PT shooting significantly with the additions of Lee, Terry and Green.  None of those guys are the same shooter Ray Allen is, but their are more _of_ them.  Together with Pierce & Bradley, we should be able to have at least 2 legitimate 3PT threats on the floor at all times.

So those things should help push the share of 3PT shots back up and the share of 'Long 2s' back down.

If we can assume (I know, I know) that our DRtg will continue to be one of the tops in the league so long as KG is breathing, these improvements on offense should help pump our ORtg back up, leading to that all-important Net Rating that we know correlates so well with winning.

This is great stuff too and I do agree.

I was amazed when I found not the decline in close 2's but the decline in 3 attempts. 3's are one of the best shots in the game, and they've been disappearing!

Part of that is because our best "close" shooter has also been our 2nd best 3 point shooter (Pierce), and that (100% subjectively) it seemed like Ray ran a lot of curl screens at the free throw line. Combine that with a PG who has a high offensive load but is allergic to 3 pointers and the fact that we have "floor spacing" bigs but no big that spaces out to the 3 line...hopefully that improves this year.

And, as discussed on the frontpage, I would like our shot selection to change, but I think I get caught up on the wording of why when you and I write.

I want shot selection to change not to get "higher percentage" shots, because the C's have always been very good at getting a high percentage of makes no matter what their shot selection. I want to see their shot selection change for the hopeful and likely small but important bump in TS if they can increase 3s and Free throws, and hopefully to get closer to average in ORebs by having offensive players near the hoop, which in and of itself would also get the C's closer to being good on offense again.

[Fan from VT]

As for playoffs:

This is very difficult. By definition, the postseason is a small sample, so you'd need to probably figure out how best to integrate multi year data. I can work on that. Not only is the postseason a small sample, but anomalies have no chance to correct due to the elimination nature of playoffs, so random noise is extremely amplified.

Further, because the timeline is short and the number of teams is small, something like the DRose injury last year is devastating in terms of stats (and to Chi fans). How do you measure that?

In the meantime, just based on the '11-'12 playoffs, here were the R^2s for various seasonal stats (i.e. using regular season stats to try to correlation to postseason success).

Note: For postseason success I simply used Playoff Wins; Utah and Dallas had 0 and Miami had 16.

Regular season wins: .247
Offensive Efficiency: .0574
Defensive Efficiency: .131
OffEff-DefEff: .3291
True Shooting: .2558
Assist Rate: .0084
Turnover Rate: .056
Rebound Rate: .0172
Pace: .0229

So no real surprises here. No strong correlations, which is to be expected with small samples and a pool already selected for the better teams.

-OffEff-DefEff seems better than regular season wins; this is to be expected as it is fairly well accepted that point differential (and offeff-defeff by extension) is more useful for predicting future wins than actual win loss record at time of prediction.

-TS has a modest correlation. Good to be efficient shooting when in the playoffs. Less strong of a correlation than in the regular season, same with point diff, etc.


-Turnovers, Rebounding, Assists, and Pace appear to have no relevance, at last based on 2012

[mmmmm]

Improved Graph 1.

-Now shows Point Diff as a league rank, showing the decreasing trend.

-Also added rank in Wins, showing the decreasing place in the standings each season.

-Note: Difficult to see both Point Diff and Wins, as the C's league rank in these two categories (not surprisingly, they are tightly correlated) were identical for most seasons.

Great job on all of this!

I'll try to toss in a few comments on the others, but the only graph I don't really like is ... this one.

The reason is, the relative rankings aren't really comparable across categories.   For example, last year, in real terms, when you pace adjust and account for number of opponent misses, the difference between being first and last in Defensive Rebounding Rate was just a couple of rebounds per game - which is almost in the game-to-game noise.   Not meaningless, but far less dramatic that appears by simply looking at the rankings of '1st' vs '30th'.   So while the chart may show a dramatic fall in the rankings from year to year in a category, it may not mean as much in real terms for one category as it does in another category.

Still, it is interesting to look at the rankings anyway.   So this is a pretty minor quibble.

Thanks for the comment mmmmmmmmmm.

I like this one, for a couple reasons with a couple caveats.

1. It is useful for looking at trends. I think that 82 games is enough that a small difference may still be significant and not just noise, and over a few seasons ends up showing trends. Trends then provide good fodder for self reflection and debate:
-Why are the trends happening? Is it decline/improvement of current players, changes in coaching, or poor/good roster changes year to year?
-How could you change the trends?
-Do you need to change the trends?
-Do the particular trends serve as a harbinger for change in other trends?
(For example on the celtics, everything has dropped off except defense. Is this because defense is totally unrelated to other things, or does it indicate slipping athleticism that will inevitably catch up to defense as well, or does it indicate that due to declining abilities the C's have had to intentionally sacrifice some areas to maintain a particular area of emphasis?)

2. The Caveat: you are right that a relative change in value does not necessarily reflect how much that impacted your team. But it shows where to look. From the other data, it does appear that TS% is about 4 times as impactful on your offense compared to ORebs, and twice as impactful compared to Turnovers. So knowing that, you can decide what/how you want to improve your team.

Edit: 3. The other thing about ranks is that for whatever reason, be it reffing, rule emphasis, etc., absolute benchmarks seem to change year to year.

For example, Last season the C's were 24th in the league in offensive efficiency, at 98.9. So you'd ask, "why can't they get back to the year before?" Well the year before they were at 104; had they duplicated that they would have ended up 7th best last season in offensive efficiency. But they were not that good in 2011, as that 104 mark was only 17th in the league!

So which is more "accurate" an expectation? That last year's C's should have been "as good as" the year before, at 104, good for 7th in the league? Or that last year's team should have been "as good as" the year before in terms of maintaining 17th place in offense.

Due to the year to year changes across the league, when looking at a team's change from year to year I think it is helpful to look at rankings to see how a team has improved or regressed.

After all, if their offensive efficiency had been 101.7 last year, it would have been "down" from 104 the year before, but it would still have been 17th place just like the year before because ALL offenses fell off last year.

Oh, certainly. I don't mean to imply that it is not useful or valuable to see both the trending or the rankings of the various categories.  They definitely are, just for the reasons you state.   

I just don't like seeing the different category rankings lumped into the same graph like that.     'Leads to mistaken impressions about how far one fell/gained in one category relative to another category - even if there is literally no comparable meaning to rank changes in the two categories.   Again, though - minor quibble.