Well, we found one thing that can stop Patrick Mahomes. An obscure rule and some confusion over when the clock has started. Kansas City scored on its first three drives, and on its fourth, with just a few seconds remaining, they tried to get into field goal range at the end of the half.
The Chiefs got to the line while the clock was stopped, in order to spike it as soon as it began, so they could save their timeout for the field goal unit. Mahomes got called for intentional grounding for spiking the ball while the clock was stopped, and it resulted in both a 10-yard penalty and the Chiefs having to use their final timeout to avoid a run-off.
It was a confusing play, though, and it will be interesting to see if the league says anything. The play clock can be seen starting before Mahomes takes the snap, so if he saw that of course he is going to think he has to get it spiked. The end result was a desperation heave for the end zone that was intercepted to end the half, the only time the Browns were able to get a stop.