We don't actually know, Oofty. Anything that people tell you about rolls is speculation/nonsense, at best, educated guessing. We don't even know
for certain, in what order the sim determines the playcall. Actually,
I don't know for certain, everyone else might...but there are many variables that interact with the roll. Energy/Morale, Player Chemistry, SAs firing on the play, Quality of the pass, accuracy of the pass, etc.
I'm thinking of the pass game here on 3rd and 8+. Everything comes down to that individual matchup between WR and his markers and the RNG. The way I think of it, consistency raises the floor of your minimum roll. I also think of it that if my my Consistency is 62, then I am operating at 62% of my capacity on 3rd downs, so my 85 man aware CB is now only a 52 man aware CB with the same reduction across all of his skills. It simulates (quite well, I think) how well your player handles psychological and physical pressure.
All of my suppositions are probably wrong - I've never built a top drone - but they're not bad, because they're consistent.
I can see that they do stupid things less often. What I
see in terms of my drones' performances is high consistency on any player really does improve their ability to make the play on 3rd down.
For me the game hangs around it to quite a large extent
So often, I will see the teams I am associated with defend superbly for 2 downs, DC has got his playcalling spot on and defenders swarm all over the offense to set up 3rd and long situations, On 3rd down, DC calls the perfect play again, but it doesn't matter the receiver caught the pass in double coverage anyway.
Or, My offense is playing really badly, their DC has got us totally sussed and pinned back, then on 3rd and whatever, our QB finds a WR with ease, The same defenders that were just destroying us on 1st and 2nd Down now look like complete morons. Players that I coach, players that I have built who are 80+ in all Coverage skills with state-approved haircuts and Apollonian physiques who are excellent CBs on downs 1 and 2, seem to have no idea what is going on in 3rd down situations. I fucking hate it when it's my CB
playing Man who just keeps on running.
The remedy I've found to keep my player consistent is 60+. Higher obviously for some positions. WRs with 70+ Consistency are lovely to have (then you moan because that he can't catch anything on 3rd down because he's spent so much on consistency that he's too slow, or he can't stand up, or he can't turn around). Nevertheless, I think that my notions about consistency being good medicine are confirmed when I drill it down into stats.
Also, I like those passive SAs that fire because it's 3rd down, they seem to help.
Disclaimer: This is intended to be illustrative and I recognize that it is anecdotal. I take no responsibility for your shitty dot 
