Updated to include 2009's closing cards and the first month of 2010, SI.com's latest mixed martial arts rankings feature changes to the middle and bottom of most weight divisions. While consistency reigns among the top three in all classes, there is expected to be considerable movement as the calendar shifts from winter to spring.
• Troubled heavyweight
• Seventh-ranked pound-for-pound fighter
• After deciding to leave their longtime haunts at 155 and 145 respectively,