So I took my first deeper dive into Williams' comp% with some other advanced metrics. One I found interesting was xComp from NFL NextGenStats. It simply computes the expected completion percentage for a QB, and then the difference between the actual Comp% and the xComp to come up with a difference value. The normal is +/- 5. Anything over +5 is " extremely lucky" and anything under -5 is terrible luck. Basically those are the non-sustainable ranges.
Looking back, it was hard for me to even find a Caleb Williams comp, a QB with over 500 attempts and Comp Diff of -5 or more. There was only one, Trevor Lawrence in 2021. He had a -5 Diff that year, and the following year, his Comp% went up 6.7% from the previous year. There were 2 other QBs with over 500 attempts, Murray in 2019 and Rodgers in 2024, but their Comp Diff were under 5. Williams is still in his own stratosphere at -6.9. There is a very high probability that his Comp% jumps 7% next year to around 65% without any actual changes, just regression to the norm. If he actually improves his own accuracy, then that could even go higher, but we will stick with the norm.
2019
Murray - 542, -3 (64.4 > 67.2) +2.8%
2021
Lawrence - 602, -5 (59.6 > 66.3) +6.7%
2024
Rodgers - 584, -4.7 (63 > 65.7) +2.7%
2025
Williams - 568, -6.9 (58.1 > ?)
On the flip side, there was one QB with a +9.1 this year, that is the highest Comp Diff since the stat was tracked. Drake Maye.
Tannehill 8.7 in 2019 on 286 attempts, dropped 4.8% the following year
Fitzpatrick 7.2 in 2020 on 267 attempts, DNP in 2021
The only other recent comparison is Burrow in 2021 had a +5.9 and his Comp% dropped 2.1% the following year.
Maye ended the season with a 72% Comp% and both him and Williams may end up next season with a comp% within 1-2% of each other. Considering they are basically 14% apart right now, that would almost seem unachievable, but the funny part is just comparing their xComps, Williams comes out on top. That is just how unlucky Williams has been (drops, etc) and how lucky Maye has been.
Williams xComp 65%
Maye xComp 62.8%