For the purposes of this study I have looked at the first sixteen starts for every NFL quarterback this century (with their first start coming in this century). A rookie in this study is a QB who is making his first through his sixteenth start. I defined a great game as a game with a passer rating of 110 or better.
I was surprised to learn that there have been 334 great games from rookie QBs this century. Drew Lock has two of those 334. Those were his game against Houston in 2019 where he posted a passer rating, PR, of 136.