“We were starting to hear of quite a few states that were running across the issue,” said Tim Lueckenhoff, president of the association. “Commissioners need to decide — are we putting the fighter in a situation where they could be harmed?”

Dr. Margaret E. Goodman, a former chief ringside physician for Nevada, said in an e-mail: “If they have a medical condition that places them at a disadvantage, then they should not be granted a license to compete. The question is whether or not Mr. Newell adequately circumvents his disadvantage.”

So far, the answer seems to be yes. In six professional bouts, Newell, who does not have a left hand, has rarely been hit or even troubled by opponents. He is scheduled to fight Friday night in Jackson, Tenn., against Chris Coggins, the first opponent in Newell’s pro career with a winning record.

In a December fight against Denis Hernandez, Newell backed him into the cage, swarming him with a flurry of fist and elbow strikes. On the ground, he wrapped up Hernandez’s foot in a painful submission.

“I didn’t know what to expect,” Hernandez said. “When he body-locked me, I felt his power. He did really well off the bat.”

To compensate for his lack of left-handed boxing technique and incomplete defense, Newell focuses heavily on footwork with his trainer Jeremy Libiszewski, working to evade strikes rather than block them. “He cuts angles, punches and gets out,” Libiszewski said.