{"id":538,"date":"2010-10-13T09:07:26","date_gmt":"2010-10-13T15:07:26","guid":{"rendered":"http:\/\/67.227.157.91\/~kenpom\/wp_blog\/roster-attrition-by-conference\/"},"modified":"2010-10-13T09:07:26","modified_gmt":"2010-10-13T15:07:26","slug":"roster-attrition-by-conference","status":"publish","type":"post","link":"https:\/\/kenpom.com\/blog\/roster-attrition-by-conference\/","title":{"rendered":"Roster attrition by conference"},"content":{"rendered":"<p>The Big Ten appears to be winning the pre-season campaign for the mostly-meaningless title of \u201cbest conference\u201d this season. They are expected to have a strong upper tier and even in terms of overall conference strength, the Big Ten may reign supreme. The conference figures to have a weak back end, but the perennial champ in this department &#8211; the ACC &#8211; isn\u2019t going to have as much junk in its trunk as it did last season. <\/p>\n<p>An additional component to this argument is that the Big Ten retains more talent from last season than any other conference in the country, or at least it should be part of the argument, because that is what the cold, hard data tells us.<\/p>\n<p>Note: The figures below are given in terms of returning offense and defense (vice returning minutes). More details after the data. <\/p>\n<pre>        <b>RetO   RetD   Avg<\/b>\nBig Ten 67.8%  70.1%  69.0%\nPatriot 68.6   66.7   67.6\nGWC     68.1   65.8   67.0\nMWC     69.0   63.9   66.4\nSoCon   67.0   63.8   65.4\nMVC     60.8   67.2   64.0\nAmEast  63.1   64.9   64.0\nIvy     62.6   65.1   63.9\nA10     60.4   65.7   63.0\nASun    60.1   65.8   62.9\nBigSth  62.3   62.9   62.6\nMAAC    59.8   65.1   62.5\nMEAC    58.6   65.1   61.8\nWCC     58.4   64.8   61.6\nC-USA   59.3   63.6   61.4\nOVC     60.8   60.5   60.7\nCAA     60.4   60.8   60.6\nHorizon 61.9   55.7   58.8\nSthland 56.0   58.9   57.4\nSummit  56.9   57.7   57.3\nACC     54.4   59.3   56.9\nNEC     54.5   59.0   56.8\nPac 10  52.9   59.4   56.2\nSunBelt 55.2   56.7   55.9\nBigWest 55.6   55.7   55.7\nBigEast 51.3   59.2   55.3\nSEC     51.3   57.0   54.1\nBig 12  50.6   55.4   53.0\nBigSky  51.9   50.5   51.2\nSWAC    46.4   55.9   51.1\nMAC     44.6   50.5   47.6\nWAC     36.1   43.8   39.9\n         \n<b>Average 57.7   60.5   59.1<\/b>\n<\/pre>\n<p>For those that must know, <b>returning offense<\/b> determines a player&#8217;s value by computing his points produced and scaling it by an additional factor that accounts for his efficiency and his involvement in the offense.<\/p>\n<p>(PlayerORtg\/TeamORtg)<sup>2<\/sup>*(%Poss\/20)<sup>2<\/sup>*(PlayerORtg*%Poss*%Min)<\/p>\n<p>In layman\u2019s terms, players that use more of a team\u2019s possessions and are more efficient than their teammates are going to be more difficult to replace. Thus their minutes are valued more in this calculation. If you still don&#8217;t get it, it means that Gordon Hayward\u2019s minutes are more difficult to replace than Avery Jukes on the offensive end.<\/p>\n<p>To compute <b>returning defense<\/b>, each player&#8217;s value is determined by computing the simple component of Dean Oliver\u2019s stops formula, <\/p>\n<p>Stops = steals + blocks x FMwt x (1-1.07 x opp OR%) + DR + (1-FMwt)<\/p>\n<p>FMwt factors in the relative value of a missed shot compared to a defensive rebound based on the team\u2019s ability to do both. And if you have any more questions about that, you should buy Dean\u2019s book. <\/p>\n<p>The benefit of each calculation is that it correlates better to year-to-year improvement than returning minutes does. <\/p>\n<p>Special thanks to John Barber for compiling returning player information. There\u2019s actually more to discuss when it comes to the reasons a player leaves his school, which John helpfully noted for me. Obviously, the majority of the cases involve a player exhausting his eligibility. But at first glance, the remaining discretionary cases don\u2019t seem to be correlated to conference visibility. <\/p>\n<p>The only obvious trend is that players in the Ivy and Patriot Leagues don\u2019t leave before they have a diploma. This isn\u2019t a surprise considering those are the only two D-I leagues where a player is at his school for academic reasons more that athletic ones. Transferring from Columbia, to say, Colorado State for an upgrade in competition (or even playing time) is not worth the tradeoff of not having a degree that says \u201cColumbia\u201d on it. In the other 30 conference, players want to play and they go elsewhere when they can&#8217;t. In addition, their tendency to misbehave appears independent of conference affiliation. I&#8217;ll document that in the future. <\/p>\n<p>And if you want team values for returning offense and defense, you\u2019ll need to buy <i>my<\/i> book (or at least the one I contributed a small amount to).<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Big Ten appears to be winning the pre-season campaign for the mostly-meaningless title of \u201cbest conference\u201d this season. They are expected to have a strong upper tier and even in terms of overall conference strength, the Big Ten may reign supreme. The conference figures to have a weak back end, but the perennial champ [&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\/538"}],"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=538"}],"version-history":[{"count":0,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/posts\/538\/revisions"}],"wp:attachment":[{"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/media?parent=538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/categories?post=538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kenpom.com\/blog\/wp-json\/wp\/v2\/tags?post=538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}