By Kevin Sweeney Plus, Michigan enters a pivotal stretch and we assess the bubble after a mixed-bag weekend. With less than a week until conference tournaments get underway and a new understanding of how the men’s NCAA tournament selection committee is thinking after Saturday’s top 16 release, it’s officially crunch time in bracket world. So what’s new after a big weekend that saw upsets, tight finishes and plenty of needle-moving wins? Sports Illustrated updates its projected field of 68 as we get closer to Selection Sunday. On the BubbleLast Four Byes:San FranciscoCreightonNotre DameIndiana …