What's hilarious is that some people read way into stats like QBR, W/L, TD's, Pics to measure a QB.
I don't think they measure pocket presence or awareness, leadership, ball protection, escape-ability to lengthen the play, ability to effectively control/manage the offense, ability to read defenses, patience to not force errors and play fakes (like play action). Montana was a master at this.
Not saying Dak is Montana (long ways from it), yet he looks to have most of these unmeasurable traits. He has his work cut out for him in the off season to improve but he's looking like he carries the foundation of a NFL starter.