Heisman Trophy betting odds can be fickle, especially so early in the season. Good performances could be fools gold, and hot starts can tail off as the calendar turns to October. And Saturday’s shift in betting odds — all kicked off by an abdominal injury for Texas quarterback Quinn Ewers — is in object lesson in such realities. Ewers entered the day as one of the betting favorites to win the award, and is now tied for the sixth-best odds, according to;%7D]9666?category=awards&subcategory=heisman) Draft Kings. Watch College Football Games Live -Try for Free Fubo! Click HERE NOW Save $30 on you…