According to Forbes Magazine, the previous record for the most 300 yard games in a player's first 40 games was 5, set by both Dan Marino and Kurt Warner.
Patrick Mahomes II broke the record last week with his 6th 300 yard game.
Patrick Mahomes II broke the record in 19 games.
https://www.forbes.com/sites/billhub.../#1211f4cb7551