here's all the times mahomes has ever been an underdog:
2018
week 1
@ la chargers: chiefs +3.5 (W 38-28)
week 2
@ pittsburgh: chiefs +4.5 (W 42-37)
week 5
@ new england: chiefs +3.5 (L 40-43)
week 11
@ la rams: chiefs +3 (L 51-54)
2019
week 14
@ new england: chiefs +3 (W 23-16)
2020
week 3
@ baltimore: chiefs +3.5 (W 34-20)
2021
n/a
2022
week 4
@ tampa bay: chiefs +1 (W 41-31)
week 6 vs buffalo: chiefs +2.5 (L 20-24)
super bowl vs philadelphia: chiefs +1 (W 38-35)
2023
divisional
@ buffalo: chiefs +2.5 (W 27-24)
career record as underdog: 7-3 (8-1-1 ATS)
we don't get many chances to bet on mahomes as a dog so we should savor it when it happens