21. Dak Prescott
Dallas Cowboys star Prescott had an outrageous rookie season as he set all kinds of records on his way to the Offensive Rookie of the Year Award in 2016. First, he threw for 3,667 yards with just four interceptions. Meanwhile, his pass completion rate was an excellent 67.8, the highest of his career so far.
However, it should come as no surprise that Prescott suffered a sophomore slump because those stats are so outrageous. But his decline was rapid as his interceptions rose from four to 13 with a significant drop in passing yards. Prescott picked himself up a season later and improved but will hope to get back to his rookie level.