1. Welcome! Please take a few seconds to create your free account to post threads, make some friends, remove a few ads while surfing and much more. ClutchFans has been bringing fans together to talk Houston Sports since 1996. Join us!

Rockets Play-by-play Analysis (2009/2010)

Discussion in 'Houston Rockets: Game Action & Roster Moves' started by durvasa, Dec 8, 2009.

  1. durvasa

    durvasa Contributing Member

    Joined:
    Feb 11, 2006
    Messages:
    37,910
    Likes Received:
    15,377
    Using the play-by-play data provided by Ryan Parker over at Basketball Geek, there's a lot we can uncover about the Rockets. I wanted to use this thread to just post whatever interesting things (interesting to me, anyway) I happen to find.

    The first topic I wanted to look into was how the Rockets offense impacts their defense, and vice versa. What do I mean by that? Well, usually we think of offense and defense as separate. But in actuality there is a relationship between the two. If you get a defensive stop, you should be able to increase your likelihood of scoring on your ensuing possession. Likewise, if your offense sputters and you miss a shot or turn the ball over, that'll help feed into the opposing team's offense.

    A lot of factors go into this. Are you a up-tempo, transition team? Then you're more likely to take advantage of your defensive stops. Are you an aggressive offensive rebounding team? Well, then you might make yourself vulnerable to other teams scoring against you. If you take a bad shot, or especially a quick, bad shot, that can kill your transition D going the other way. And of course who you have on the floor would also have an impact.

    As a preliminary study, I ran through every possession the Rockets played this season on offense and defense. I reasoned that the possession I'm interested in could have one of 5 outcomes:

    (1) Ended in a made free throw (due to a foul)
    (2) Ended in a missed free throw
    (3) Ended in a made field goal
    (4) Ended in a missed field goal
    (5) Ended in a turnover

    While a "defensive stop" is typically defined as holding an opponent to 0 points on a given possession, for my purposes here I'll treat as stop as a possession ending with either (4) or (5).

    Below, I've created tables that describes each possession (the rows), given the outcome of the prior possession (the columns). The first table is focusing on the Rockets offense, so the rows correspond to Rockets offensive possessions, while the columns are the their prior defensive possessions. And for the second table, we're looking at the outcome of the Rockets defensive possessions (the rows) given their prior offensive possession (the columns).

    Consider in the first table, the cell for row "MADE FG" and column "MADE FG". It reads 595/264. This means that there were 264 such possessions (a Rockets possession ending in a made field goal, following a defensive possession that ended in a made field goal). And over those 264 possessions, the Rockets scored a total of 595 points (or about 2.25 points per possession).


    Rockets on Offense:

                MADE FT     MISSED FT   MADE FG       MISSED FG   TURNOVER
                -------------------------------       ---------------------
    MISSED FT   4/4         0/1         16/17         17/15       7/8
    MADE FT     51/23       10/4        132/65        95/50       57/27
    MADE FG     161/74      29/13       595/264       499/222     291/136
                -------------------------------       ---------------------
    MISSED FG   0/75        0/17        0/224         0/195       1/83
    TURNOVER    0/25        0/7         0/126         0/80        0/59
                -------------------------------       ---------------------
                107.5       92.9        106.8         108.7       113.7
                -------------------------------       ---------------------
                           106.3                            110.5           



    On the second to last row on the Rockets Offense table, I summarize our offensive efficiency on possessions following each type of defensive possession. So, when a Rockets defensive possession ends in a made field goal for the other team, their offensive efficiency in the ensuing is 106.8. On the other hand, when the Rockets are able to create a turnover, their offensive efficiency jumps up to 113.7. Overall, the Rockets improve their offensive efficiency by about 4 points when they get a "stop".

    Now the defense ...

    Rockets on Defense:

                MADE FT     MISSED FT   MADE FG       MISSED FG   TURNOVER
                -------------------------------       ---------------------
    MISSED FT   8/6         0/0         12/13         12/13       4/5
    MADE FT     29/15       2/1         142/66        141/76      63/31
    MADE FG     144/67      39/19       508/236       479/221     268/126
                -------------------------------       ---------------------
    MISSED FG   0/52        0/19        0/240         0/157       0/69
    TURNOVER    0/30        0/6         1/123         0/94        0/53
                -------------------------------       ---------------------
                106.5       91.1        97.8          112.7       118.0
                -------------------------------       ---------------------
                            99.1                            114.4       


    This I found somewhat troubling. When the Rockets are able to get to the line or make a field goal, their defense in the ensuing possession is awesome -- holding opponents to a 99.1 defensive efficiency. But look at what happens when their possession ends in a missed field goal or a turnover. Their defensive efficiency is awful.

    Why the huge discrepency? Two things come to mind. First, the Rockets are crashing the offensive boards this year. That works out great when they get it. But when their scrappiness goes unrewarded, their transition defense is compromised. Perhaps this analysis is unfair to the Rockets, because they are very good at getting to those offensive boards (in a subsequent study, I could look at defensive efficiency after possessions on which the first shot attempt is a miss).

    The second reason is that with the Rockets looking to run more in transition, when their possession ends early that gives the opponent an opportunity to run right back on them. There is opportunity here as well for further examination of the play by play to see when exactly the Rockets are hurting themselves. Should they cut down those early 3-pointers, for instance?

    That's all for now. I welcome any comments.
     
    #1 durvasa, Dec 8, 2009
    Last edited: Dec 8, 2009
  2. Slimjim19

    Slimjim19 Member

    Joined:
    Sep 18, 2009
    Messages:
    994
    Likes Received:
    12
    Great analysis!

    The thing that pops out at me is the Rockets on Defense part. We're definetely crashing the boards more this year, and it's paying dividends with all those offensive rebounds. It probably does effect our transition D a bit because it takes a lot of energy to go for offensive boards.
     
  3. larsv8

    larsv8 Contributing Member

    Joined:
    Nov 11, 2007
    Messages:
    21,663
    Likes Received:
    13,913
    I like the work you put in, great job!

    I wonder if there are conclusions to be drawn here outside "opponents score more off missed shots and turnovers than made shots". Naturally on missed shots/turnovers there is less court to cover for the offensive team to get to the basket which means less time for the D to get set, but how I am curious how much of it mental.

    I would also like to see the data with it just missed shots and not turnovers. Turnovers can skew a little because of breakaway dunks, etc.
     
  4. trugoy

    trugoy Member

    Joined:
    Nov 23, 2002
    Messages:
    1,383
    Likes Received:
    139
    I am sure this is the case with every single team in the league, what would be more interesting is if it was correlaled compared to the league average or vs other teams.
     
  5. Carl Herrera

    Carl Herrera Contributing Member

    Joined:
    Feb 16, 2007
    Messages:
    45,153
    Likes Received:
    21,570
    Very cool, how do they compare to last year's numbers?
     
  6. xiki

    xiki Contributing Member

    Joined:
    Jun 18, 2002
    Messages:
    17,491
    Likes Received:
    2,883
    Interesting. What about by 1/4; starters v subs; which players correlate their numbers better/worse?
     
  7. No Chance

    No Chance Contributing Member

    Joined:
    Jun 22, 2000
    Messages:
    967
    Likes Received:
    133
    Durvasa very outstanding work. Need to change your handle to Mr. Morey jr.

    Lot of good info!
     
  8. J.Will.Xu

    J.Will.Xu Member

    Joined:
    Aug 21, 2008
    Messages:
    1,715
    Likes Received:
    7
    Brilliant breakdown on both offense and defense, thanks sir.

    Defensive efficiency really kills us when we crash the board more than ever and didn't get the boards, at the moment the trans D would be the most vulnerable no matter we got our defense set right away, it's gonna either be a bucket or a foul to send the opponent to line.
     
  9. mikol13

    mikol13 Protector of the Realm
    Supporting Member

    Joined:
    May 31, 2009
    Messages:
    13,774
    Likes Received:
    27,147
    Great post as always. keep up the good work, it is much appreciated
     
  10. Deckard

    Deckard Blade Runner
    Supporting Member

    Joined:
    Mar 28, 2002
    Messages:
    56,793
    Likes Received:
    39,077
    You need to hook up with thacabbage doing the stats on his new gig, Durvasa. :cool:
     
  11. durvasa

    durvasa Contributing Member

    Joined:
    Feb 11, 2006
    Messages:
    37,910
    Likes Received:
    15,377
    Basketball Geek has the play-by-play data for 72 of the 82 games last year. Good enough to make a comparison.

    Rockets on Offense (08/09):

                MADE FT     MISSED FT   MADE FG       MISSED FG   TURNOVER
                -------------------------------       ---------------------
    MADE FG     422/191     149/68      1967/872      1880/846    728/330
    MISSED FT   12/16       6/6         59/57         40/33       22/23
    MADE FT     130/66      26/12       537/269       425/224     182/93
                -------------------------------       ---------------------
    MISSED FG   1/198       0/48        1/778         0/714       4/277
    TURNOVER    0/111       0/24        0/380         0/346       0/126
                -------------------------------       ---------------------
                97.1        114.6       108.8         108.4       110.2
                -------------------------------       ---------------------
                            106.9                           108.9       


    Compared to last year, the Rockets are a little better at converting their "stops" into improved offense. Last year, per 100 possessions, their efficiency increase +2. This year, its +4.


    Rockets on Defense (08/09):

                MADE FT     MISSED FT   MADE FG       MISSED FG   TURNOVER
                -------------------------------       ---------------------
    MADE FG     551/253     106/49      1879/864      1632/743    951/444
    MISSED FT   6/13        1/1         65/62         53/54       29/29
    MADE FT     127/65      12/9        465/230       382/201     147/80
                -------------------------------       ---------------------
    MISSED FG   0/263       0/52        0/859         1/681       1/308
    TURNOVER    0/76        0/19        1/325         0/301       0/143
                -------------------------------       ---------------------
                102.1       91.5        103.0         104.4       112.4
                -------------------------------       ---------------------
                           102.3                            107.1       


    Here, we see that our defense improved by about 5 points per 100 possessions when we're able to score a field goal or get to the line. Allowing 107.1 efficiency when we're "stopped" doesn't look bad at all, compared to what we've done so far this year.
     
  12. durvasa

    durvasa Contributing Member

    Joined:
    Feb 11, 2006
    Messages:
    37,910
    Likes Received:
    15,377
    Data for just missed shots is in the table.
     
  13. larsv8

    larsv8 Contributing Member

    Joined:
    Nov 11, 2007
    Messages:
    21,663
    Likes Received:
    13,913
    Oh I misinterpretted.
     
  14. Sweet Lou 4 2

    Sweet Lou 4 2 Contributing Member
    Supporting Member

    Joined:
    Dec 16, 2007
    Messages:
    37,714
    Likes Received:
    18,912
    Your defense will always be superior after a made bucket than a missed one or a turnover. That is an axiom of basketball.

    The reason is three-fold.

    One, a made field goal requires the opposing team to inbound the ball. This requires a few seconds to first get the ball, walk out of bounds and then pass it back in. This allows the team that just made it's shot more time to back and get set on whatever defensive schema.

    A missed shot or turnover the ball is immediately in play - far less time.

    Second - a missed field goal and turnover results in the ball already being advance already closer to the opposing basket than an inbounds. There's less distance to cover.

    Third - the ball is most likely already advanced of at least one opposing defensive player. This results in 5-4, 4-3, 3-2, 2-1, 1-0 situations which are very high scoring.


    This is why turnovers are a double hit. Also, who misses the shot can make a difference. If a small guard gets past his man at the top of the key and then misses a layup which is rebounded by a big, that big can then pass to the guy who blew his assignment and the top of the key and he will be ahead of his defender who is still in the paint. Finally, another reason why shot-blockers are more valuable than just preventing a score.
     
  15. Carl Herrera

    Carl Herrera Contributing Member

    Joined:
    Feb 16, 2007
    Messages:
    45,153
    Likes Received:
    21,570
    Good stuff. A few thoughts:

    1. In both years, the Rockets struggled on D after turning the ball over. Not a surprise, because pretty much every team struggles to one extent or another when turning the ball over.

    2. The Rockets did quite a bit worse this year after TOs than they did last year. Here's my theory: a perimeter player turning the ball over is typically worse than a post player doing so. Last season, Yao Ming was by far the Rockets TO leader, followed by Artest, Brooks and Scola. This year, it goes Ariza, Brooks, Scola and Lowry. I am thinking that when Yao turns it over, the Rockets perimeter guys are more ready to play transition D, but when, say, Ariza turns it over, the transition D is mroe screwd. If he's penetrating, then the Rockets are one transition defender down. If he's hanging around the 3 point line, then there's not much defense behind him, either.


    3. I think the most interesting thing what happens to Rockets D between Rockets missed FGs and the Rocket make FGs. You can see, roughly the benefit and cost of board crashing between the years:

    Benefit: Increase OReb% from .264 to .306
    Cost: Decreased effectivness of transition D, where as Rockets lost 1.4 points per 100 possession on D (103 vs. 104.4) after missed shots compared to after made shots, now they lose a whopping 14.9 points (97.8 vs. 112.7) after missed shots compared to after makes.

    When I get a chance, I'd like to run some calculations as to whether it is "worth it" but will have to think some more.


    4. The Rockets half-court D (i.e. D after "static situations" such as made baskets, made FTs and missed FTs) are actually better this season than it was last. Somewhat interstingly, after losing the slowest member of the team, and probably the last guy to get back on transition, it is their transiton D (after TOs and after missed shots) that is suffering.

    As discussed above, it seems likely that what's going on is that the Rockets are compensating for the loss of offensive talent by doing things that boost offense but hurts D. It's a tradeoff that I am guessing Morey's guys calculated to be worth it.

    Remember how basketball video games have this bar where you can decide how much you want to crash boards vs. get back on transition? The Rocket have moved the bar way over to the "crash boards" side.

    (They are also getting on fast breaks more, which is likely at the cost of defensive rebounds... but that is not reflected in these numbers here).

    In StarTrek terms, I am guessing what Captain Adelman does is called "diverting power from shields to disruptor."



    5. The Rocket difference in defensive efficiency after made FTs and after made FGs this year has got to be a fluke.
     
    #15 Carl Herrera, Dec 8, 2009
    Last edited: Dec 8, 2009
  16. bjshot

    bjshot Member

    Joined:
    Jul 11, 2006
    Messages:
    912
    Likes Received:
    4
    great research.

    One name comes to my mind. JVG. Coach JVG is very against TO, that's why he didn't play that Greek pg. When the pg/ballhandler had TOs, it usually transfer to easy basket and generarte 'the momentum'. That's why rafer is a very good PG. He didn't make this kind of TOs and can forced TOs.

    That's why I don't like coach RA even though he's a great coach. 'Gun and run' can't win champaignship because they'll sacrifice defense and give up easy basket. John starkton couldn't score like nash, but he is better than Nash because he's a defense powers, he had less TOs and controlled tempo better.
     
  17. bjshot

    bjshot Member

    Joined:
    Jul 11, 2006
    Messages:
    912
    Likes Received:
    4
    I mean, team defense or transition D is suffered because of TOS.
     
  18. durvasa

    durvasa Contributing Member

    Joined:
    Feb 11, 2006
    Messages:
    37,910
    Likes Received:
    15,377
    I hadn't thought of it that way, but that could be playing into it. I can check to see if certain players' turnovers are more costly than others.

    My theory is that because the Rockets are playing more up-tempo this year and taking quicker shots without really setting up their offense, this puts them out of position defensively when they aren't able to capitalize. How often do we see a team go for a quick shot on a fast break and miss, and then the other teams run it right back on them? This must be happening to the Rockets more frequently this year than last year.
     
  19. Depressio

    Depressio Contributing Member

    Joined:
    Mar 3, 2009
    Messages:
    6,416
    Likes Received:
    366
    I find it astonishing that our half-court defense (after made FG/FT, missed FT) is actually better now.
     
  20. dtrain0928

    dtrain0928 Member

    Joined:
    Jun 26, 2009
    Messages:
    217
    Likes Received:
    27
    show off! :grin:
     

Share This Page

  • About ClutchFans

    Since 1996, ClutchFans has been loud and proud covering the Houston Rockets, helping set an industry standard for team fan sites. The forums have been a home for Houston sports fans as well as basketball fanatics around the globe.

  • Support ClutchFans!

    If you find that ClutchFans is a valuable resource for you, please consider becoming a Supporting Member. Supporting Members can upload photos and attachments directly to their posts, customize their user title and more. Gold Supporters see zero ads!


    Upgrade Now