Bill O'Brien hands play-calling duties to Texans OC

nfl.use("nfl-video", function (Y) { supportsFlashVideo = Y.NFL.Video.supportsFlashVideo, nfl.videoplayers[srcId] = vp = new Y.NFL.Video.Player({ flashAdTag: "http://pubads.g.doubleclick.net/gampad/ads?sz=640x360&iu=/4595/nfl.news/story&ciu_szs=300x250&impl=s&gdfp_req=1&env=vp&output=vast&unviewed_position_start=1&cust_params=slot%3Dvideo%26url%3Dstory%26prtnr%3Daround-the-league%26team%3Dhou%26conf%3Dafc%26dvsn%3Dacs%26plyr%3Ddeandre_hopkins%26plyr%3Dderrick_watson%26s1%3Dstory&url=[referrer_url]&description_url=www.nfl.com&correlator=[timestamp]" html5AdTag: "http://pubads.g.doubleclick.net/gampad/ads?sz=640x360&iu=/4595/nfl.news/story&ciu_szs=300x250&impl=s&gdfp_req=1&env=vp&output=vast&unviewed_position_start=1&cust_params=slot%3Dvideo%26url%3Dstory%26prtnr%3Daround-the-league%26team%3Dhou%26conf%3Dafc%26dvsn%3Dacs%26plyr%3Ddeandre_hopkins%26plyr%3Dderrick_watson%26s1%3Dstory&url=[referrer_url]&description_url=www.nfl.com&correlator=[timestamp];ord=" + nfl.constants.AD_RANDOM + "?" Kelly followed O'Brien to Houston in 2014 and has climbed the coaching ladder year after year, his promotion to offensive coordinator last year the latest step up before Tuesday's news.Soon to be 34 years old, Kelly is one of the youngest offensive coordinators in the league and will certainly be one of the youngest play-callers.Over the past three seasons, with O'Brien calling the plays, Houston has stayed around the league average in both points and yards per game.