{"id":655,"date":"2006-06-09T03:50:55","date_gmt":"2006-06-09T09:50:55","guid":{"rendered":"http:\/\/67.227.157.91\/~kenpom\/wp_blog\/back-in-the-lab\/"},"modified":"2006-06-09T03:50:55","modified_gmt":"2006-06-09T09:50:55","slug":"back-in-the-lab","status":"publish","type":"post","link":"https:\/\/kenpom.com\/blog\/back-in-the-lab\/","title":{"rendered":"Back in the Lab"},"content":{"rendered":"<p>In no other sport is there such a controlled experiment as the free throw. While statistical analysis of basketball can be more challenging than other sports in numerous ways, at least we have this. And it&#8217;s about time we took advantage of it. <\/p>\n<p>Specifically, there is a weak connection between 3-point shooting and free throw shooting. Even though the connection is weak, it does appear that we can use it to our advantage when projecting how a player&#8217;s 3-point accuracy will change from one season to the next. <\/p>\n<p>In this exercise, I took the top 100 returning players ranked by their 3-point attempts in 2005. Everyone from Syracuse&#8217;s Gerry McNamara (315 attempts in &#8216;05) to Lipscomb&#8217;s James Poindexter (165). I labeled the top 33 by accuracy as &#8220;good&#8221; 3-point shooters, and the bottom 33 as &#8220;bad.&#8221; I then sorted them by free throw accuracy in the same manner. <\/p>\n<p>One thing to note is that this group shot about the same on 3&#8217;s in &#8216;05 (37.7%) and &#8216;06 (37.5%). In addition, 3P% is not well-correlated on an individual level from year-to-year, with a correlation coefficient of .371. To illustrate what that means, the following plot shows how well each member of this group shot 3&#8217;s in &#8216;05 and &#8216;06. You can see some relationship, but there&#8217;s quite a bit of scatter.<\/p>\n<p><img src=\"\/images\/threes0506.gif\" \/><\/p>\n<p>The lack of year-to-year correlation and nearly steady mean of the population provides another tool to use in a prediction &#8211; the concept of regressing to the mean. For instance, of the 33 good shooters in &#8216;05, only 8 improved their accuracy in &#8216;06. Of the bad shooters, 19 showed improvement the following season. So knowing nothing else, we can predict that the best shooters will see a decline and the worst shooters will improve. <\/p>\n<p>But adding free throw shooting into our primitive model appears to increase the certainty of a prediction for a select few players. Of the 3-point shooters I labeled &#8220;bad&#8221; based on their &#8216;05 performance, eight of them happened to be good free throw shooters. The list:<\/p>\n<pre>                       2005  2005  2006    3P%\nPlayer                  FT%   3P%   3P%   Diff\nBettencourt, Bucknell  88.8  35.3  40.3  + 5.0\nMcNamara, Syracuse     87.4  34.0  33.4  - 0.6\nWashington, Delaware   87.2  34.5  39.6  + 5.1\nGolob, N. Arizona      85.2  34.7  42.8  + 8.1\nGardner, Missouri      83.1  27.0  39.7  +12.7\nBrown, CS Fullerton    82.7  34.8  37.7  + 2.9\nKruger, Arizona St.    82.1  35.4  40.3  + 4.9\nWilliams, Long Island  81.3  35.7  41.8  + 6.1\nAverage                85.0  33.9  39.4  + 5.6<\/pre>\n<p>Seven of the eight shooters improved in &#8216;06, and the improvement was substantial in many of the cases. By comparison there were 11 players that were bad outside shooters and bad free throw shooters, and only 3 of them improved their 3-point shooting.<\/p>\n<p>Now let&#8217;s look at the opposite group &#8211; the good shooters in &#8216;06 that were unusually poor from the line. I should point out that the 100 players as a whole were much better free throw shooters than the general college hoops population (77.8% vs. 68.7%). Therefore, one must shoot better than 74.4% from the line to avoid being in the &#8220;bad&#8221; free throw shooting group for the sake of this discussion. <\/p>\n<p>There were nine players that fell into the bad free throw shooting\/good 3-point shooting group in &#8216;05.<\/p>\n<pre>                       2005  2005  2006    3P%\nPlayer                  FT%   3P%   3P%   Diff\nStewart, USC           58.8  40.0  39.7  - 0.3\nJointer, S. Alabama    65.4  39.7  33.7  - 6.0\nAgudio, Hofstra        65.8  42.3  42.1  - 0.2\nTrotter, Alabama A&amp;M   68.1  40.0  35.8  - 4.2\nDixon, Troy            69.0  39.9  38.0  - 1.9\nSmith, Houston         70.3  40.2  34.9  - 5.3\nButler, George Mason   73.6  43.1  37.8  - 5.2\nCarroll, Utah St.      73.8  47.6  45.1  - 2.4\nWinters, Davidson      74.0  43.4  33.9  - 9.5\nAverage                68.8  41.8  37.9  - 3.9<\/pre>\n<p>Every one of the nine saw a drop in their 3-point shooting in &#8216;06, although the effect was not as dramatic as for the first group, perhaps because free shooters labeled as bad by me aren&#8217;t really that bad in the grand scheme of things. For instance, nobody at Hofstra was concerned about Antoine Agudio&#8217;s 0.2% drop in accuracy. He was still excellent from beyond the arc. By the way, for the 15 good 3-point shooters that were also good free-throw shooters, only eight were worse 3-point shooters in &#8216;06.<\/p>\n<p>The funny thing about the two not-so-random groups listed above is that while the good shooters outshot the bad ones by an average of 7.9% in &#8216;05, the same group of bricklayers actually outshot the good shooters in &#8216;06 by 1.5%.<\/p>\n<p>I have a couple of cautionary notes, though. First, there are plenty of exceptions to be found. They include Troy&#8217;s Jacob Hazouri had shooting numbers of 36.8\/60.0, and saw his 3-point shooting rise to 41.1% in &#8216;06. On the one hand his 60% free throw percentage was only on 20 attempts, but on the other, he shot 56.4% in 39 attempts from the line in &#8216;06. At the other end, St. Peter&#8217;s Keydren Clark posted 36.7\/83.5 in &#8216;05, but saw his 3-point shooting dip to 32.6% in &#8216;06. There are a bunch of others out there.<\/p>\n<p>Second, I have to add the obligatory note that context also plays a role here. One notable player that just missed making the last list was Dee Brown. In 2005, he shot 43.4% from 3, and a pedestrian (for this group) 77.2% from the line. Knowing this, we would have expected Brown to come back to the pack slightly on his 3-point accuracy in 2006, even had his supporting cast remained the same, if only due to the pull of the mean for 3-point shooting. Of course, he lost two of his teammates to the NBA, and that had much to do with his tremendous drop in 3-point accuracy to 32.1% in 2006. <\/p>\n<p>In my next post, I&#8217;ll use the dual power of regressing to the mean and free throw shooting to examine some interesting cases for 2007. And there are plenty of them.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In no other sport is there such a controlled experiment as the free throw. While statistical analysis of basketball can be more challenging than other sports in numerous ways, at least we have this. And it&#8217;s about time we took advantage of it. Specifically, there is a weak connection between 3-point shooting and free throw [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/posts\/655"}],"collection":[{"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/comments?post=655"}],"version-history":[{"count":0,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/posts\/655\/revisions"}],"wp:attachment":[{"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/media?parent=655"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/categories?post=655"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/tags?post=655"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}