Not to be a critic here, but his first game start was the last game of his rookie season. The Denver game was a regular season game of the year before he became a full time starter.
The first fact is already wrong. Who made this video? Clearly someone who doesn't know anything about Mahomes. "The Chargers were 12 to 4 that year." 12 to 4. 12 to 4?? TO??? Have you ever watched football? You clearly do not follow football and are just trying to cash in on Mahomes right now.