I don't get it. I've seen plenty of games where there were clearly some adjustments made at halftime.
When we had Coach O and Les Miles, you just knew that if we were down at halftime we were going to lose that game. It was the most hopeless feeling.
Well I’ve said before what’s adjustments, you look at your playbook and now you are calling plays for your talent that is much better than yours, and you assume the more bites at the apple, the more likely you are to get something to pop, lane did this a lot
But the perfect example was Florida with Percy, it was a drive they hit him a couple times, and then from the backfield he lined up next to Tebow and then ran a route with terrible coverage because his position on the field and he made a house call, rarely are people throwing out the playbook or doing stuff, you may have a quick conversation like what are you seeing etc with a specific position and their coach then they are talking to the guys upstairs, also having all those eyes in the both may tell you damn they keep lining up like this so try this, also keep in mind a lot of plays in the first half are to see what the defense does and reacts to play against that tendency
On offense I can honestly imagine this being the case. Offenses are constantly reacting to defenses in the immediate and every drive depending on down and distance and personnel...so at some level your offense is your offense. If they're stopping the run it doesn't matter if it's 1Q or 4Q, good coaches adjust when they adjust.
On defense, you have a half to see what is working what is not and have the perspective to see weaknesses specific to your personnel that you might not have known in the 1Q, especially college. Michigan was unquestionably a second half defensive team thru half time adjustments.
Manning never did half time adjustments because he was likely aways doing it.
Even on defense it’s not like you think, defense is ever harder to install things during the season let alone mass scale things, which is why when Don tried to add zone nikkas was nuttin up, it’s, ok the formational approach to a play they keep stinging us on needs to change so we may call a cover 3 with a rat in the hole to trick them into thinking the post or the dig is there, or hey they doing that one play based on alignment because the ocs stuck, and I’m going to gamble ( think the osu game with double flats from the edge rushers and ol boy almost got his paws on an int) or doing an inverted cover 2 to confuse stroud, that was a tendency breaker it happened to work