Showing posts with label 3-pt shooting. Show all posts
Showing posts with label 3-pt shooting. Show all posts

Monday, January 10, 2011

The team that can't shoot straight

While there is undoubtedly much moaning and gnashing of teeth in Hoya-land these days, it's important every once in a while to step back and wonder whether your current mood is based upon small sample-size results.

To wit, one of the biggest drivers for Georgetown's current swoon is the complete loss of an outside shooting touch.  If you take a look at the Team Stats breakout page, you'd find that the team shot 42.6% on 3FGs in the non-conference season, but has only hit them at 25.7% over the first four conference games.

To put this difference into some context, I've gathered the final non-conf. and conf. 3FG shooting percentages for all Georgetown seasons since the 3FG game into the game (1986-7).  This may have been a herculean effort in the past, but thanks to the stats pages over at the Georgetown History Project, it's now a trivial exercise.


As you can see, how well a team shoots from behind the arc in the non-conf. portion of the schedule is generally a good predictor of how well it will shoot in Big East play.  Until this season (that big black dot in the lower right).

How well are the two shooting percentages correlated?  Glad you asked:


There's a bit more going with this graph, so allow me to explain all those lines:
  • The blue line is the 1:1 line.  Points above the line are when the team shot better in conference, points below the lne are when the team shot better out-of-conference.  Since competition in the non-conf. portion of the schedule is weaker, you'd expect most of the points to be below this line, which they are.
  • The thick red line is the linear fit of the data, for all seasons except this year.  That R2 number refers to the goodness of fit of this line.
  • The dashed lines are the 95% prediction bands, based on the fit.  That is to say, there is only a 1 in 20 expectation that a data point would fall outside of the dashed lines.  And this is just what we see:  there are 24 seasons that make up the dataset, and only one would be considered an outlier (1989-90).

In the four Big East games played so far, Georgetown's lousy outside shooting is an extreme outlier.  As we said at the top, the team is shooting 25.7% on 3FGs, while we'd expect them to be making 37.4%, based upon the OOC performance.

Using the stats from previous seasons, there's about 0.12% chance that Georgetown will end the conference season shooting this poorly.  In terms of odds, that's 850:1 against.

So chin up Hoya fan!  It's going to get better.

It has to.

I hope.

    Thursday, March 12, 2009

    Season Post-Mortem, Part II: Shooting

    For the past few years, the Hoyas' offense has been effective primarily because the team takes good shots and makes them. This makes sense: shooting percentage is by far the most important of the "four factors" in terms of driving a strong offense. You have to make shots.

    This should not be news to anyone.

    This year, the Hoyas' effective shooting percentage was not strong. It was the worst of the Thompson era, and driven primarily by an awful three point shooting percentage.

    Below is a chart of 3Pt% of each player and the number of threes they took, ranked by highest 3 pt % (minimum 50 shots).

    Rank   2005%/Shots   2006%/Shots   2007%/Shots  2008%/Shots  2009%/Shots
    1 40%/60 44%/119 49%/149 45%/159 39%/124
    2 39%/137 41%/120 38%/96 41%/151 36%/89
    3 38%/162 38%/132 33%/127 40%/100 33%/79
    4 37%/126 32%/92 30%/135 34%/139 33%/89
    5 37%/148 29%/91 - - -
    Rem. 24%/51 25%/56 35%/121 31%/132 28%/156

    Overall, the Hoyas under John Thompson III have done a good job of having their best shooters take the most threes. In the early days with Ashanti Cook, DJ Owens and Jon Wallace, the Hoyas had three consistent three point shooters. Jeff Green and Brandon Bowman added years with nice shooting.

    Since then, the level of shooter has declined. In the Final Four year, only Wallace and Green were all that effective as higher volume shooters, but Tyler Crawford and Pat Ewing had nice percentages to buoy the team in the remainder column.

    Last year, it was Wallace again, as well as Austin Freeman and Jessie Sapp.

    This year, there's been three main problems:

    First of all, there's no Jon Wallace. DaJuan Summers has really picked up his shooting, but Wallace's mid to high 40's percentages are hard to replace.

    Secondly, the team is giving way too many shots to players who cannot shoot. Jessie Sapp shot 36% and only took 89 shots -- by far the lowest total for the second highest shooting percentage on a team in the last five years. In contrast, we gave 156 shots to a group mostly made of bench players that collectively shot 28%. The rotation was too large for a team with very few shooters.

    Lastly, Austin Freeman and Chris Wright didn't shoot well. Both shot over 40% last year. Both shot 33% this year. Wright has always been a streaky shooter and his FT % implied his dropoff might come. But Freeman's key offensive asset is his shot. The team just couldn't sustain an offense with one three point threat on the floor most of the time in Summers.

    Wednesday, December 31, 2008

    "Stop Taking Threes!"

    That's been a common refrain in sports bars, living rooms and chat rooms for Hoya fans since John Thompson, III has become coach. For the most part, it's been justified. There's no doubt that when the Hoyas become lazy on offense, they tend to jack up the easy shot, which is often a three.

    I've long been a defender of shooting the three in college ball. Because of the added point and a relatively close line, it's not a bad shot. It's a better shot than anything from 15' to 20', provided they are both open.

    That said, there's no doubt that it should be part of a team's arsenal, not all the team can get. A great offense takes open threes it wants. It does not settle for the shot.

    If you look at the last few national champions, you'll also notice a bit of a trend in the teams percent of three-point shots attempted per FG attempt:

    Year   Champ         3PA/FGA
    2008 Kansas 29.3%
    2007 Florida 34.0%
    2006 Florida 34.8%
    2005 North Carolina 30.4%
    2004 Connecticut 25.8%
    (median is 33.0%, but % range from 19% to 52%)

    For some reason, the next couple of winners have slipped my mind. Needless to say, though, National Champs don't rely exclusively on the three, and often almost ignore it (relatively speaking). Florida's title winners were much more three minded than most, and even their ranks were in the mid-100s. In other words, average for DI, but probably above average for a major conference team (mid-majors and low majors tend to be a bit more dependent on the three).

    It's not that teams who do not rely on the three are necessarily better because of that choice; it's that better and more talented teams rely on it less because they have other, better options. If you have a great low post player (which champions tend to have), great offensive rebounding or penetrating point guards, you tend to get a lot more dunks and layups and need to shoot threes less. Of course, you also draw more fouls, but we'll get to that.

    Under Thompson, the Hoyas have been somewhere between 35% and 42%. When Jeff Green and Roy Hibbert were both on the team and playing big minutes together, the Hoyas had a 3PA/FGA of 37% and 35%. In the other years, it's been 43% and 40%.

    The Hoyas are currently sitting at 39%.

    This is not particularly surprising. With only one post player and a burgeoning crowd of elite perimeter players, this shouldn't seem odd.

    Now this might be a bit discouraging to Hoya fans. After all, none of those prior National Champs had a number that high. And it's nowhere near the number in 2006-7, the most successful season under Thompson.

    But wait! The number is also a bit deceptive, because it doesn't include free throws. Free throws don't register as a field goal attempt, but they are most often the equivalent of a shot taken, and when they are, they are almost always on a two point attempt. In other words, the more a team draws fouls, the more their 3PA/FGA is overstated relative to a team that doesn't draw fouls.

    Here's another way to think about it. Using the proxy of .43 shots per FTA (adjusting for one and ones, hoop and the harms, etc.), here's how the % of shot attempts breaks down for the last three years:

    Year3 PT2 PTFT
    2006-0730%56%14%
    2007-0835%52%13%
    2008-0931%49%19%

    Now, some of those free throws are one and ones, end of game fouling, etc., so they aren't all off two point shots. Still, the percentage of shots taken from three is actually much closer to the Final Four year than it is to last year.

    It doesn't mean the Hoyas are going to the Final Four, but it does indicate that the Hoyas have a more diversified offense this year. And that should pay off when the shots aren't falling.