In MMA, as in most sports, competitors must continuously improve and evolve to reach the highest level.
Even once a fighter makes his way to the top, he must keep working to ensure contenders aren't closing the gap. Jon Jones is widely considered the best fighter in the world right now, but he's holding onto that title by putting in the work at Jackson-Wink MMA to ensure he maintains a gap between him and the rest of the light heavyweight division.
There are always areas that some of the best in MMA could still work to improve.
With that said, here are the Top 15 UFC fighters and their most needed improvements. As a note, the following rankings are based on the official UFC rankings, which are voted on by various members of the MMA media.