The AFC West has a problem, and he is only 23 years old and has four career starts. Kansas City quarterback Patrick Mahomes arrives for Monday night’s game against the Broncos as one of the league’s best stories. During a 3-0 start, he has ranked first in touchdown passes (13, an NFL record for games 1-3), passer rating (137.4) and completions of at least 25 yards (12). The transition normally reserved for a young passer has been replaced by consecutive lights-out performances against the Los Angeles Chargers, Pittsburgh and San Francisco. “He’s throwing the (heck) out of the ball to everybody,” Broncos linebacker Von Miller said.