QB stats. There are a million of these. But, if you want to compare their actual relative performances let's figure out a new stat. Take the total number of drop backs, subtract all throw aways, factor in
the average time In total seconds each QB had from snap to release. Then grade each targeted throw. Did it hit the target? On a scale of 1-5 (5 bring a perfect throw to the receiver's hands with enough lead for YAC. I actually don't care if the receiver caught it , dropped it or tipped it as that goes beyond the QB's responsibilities. The only other factor is did the receiver run the right route? How many times did a receiver run an out rather than an in and the FS snags the interception? That would be it for me. Having great receivers skews the stats for the QB. Receivers dropping passes hurts the completion percentage. Tipped passes can lead to interceptions which kill QBR.
And there's no fair way to compare passers without comping their time in the pocket. Brady is a very good QB, but he has all day to throw. If Goff has under two seconds to throw and TB has four how do you compare them? TB gets lauded for going through his progressions. He has time to. Goff drops back looks and is hit from behind and fumbles. So now he sucks? Nope. One of his guys missed a block. Anyway, there's my three cents.