when to call man coverage

i kno this maybe a noob question and i dont consider myself a noob but wen should u call for man coverage?...i kno not on third and short but for someone doing either simple routes or jus routes that man should be able ta keep up with out make ppl think twice and that the windows are too open in zone...it jus seems like every time i call man i get burnt for 20 yards..i dont have lb's covering wr's i even have cb's covering TE's and still get burnt for atleast 20 so can anyone let me kno when to call man wat situations to call man caus sometimes i need ta switch up and call man caus i call zones too much.

3rd and long/ 4th and long (usually quarter 3 deep contain, something like that)

yeah i use that play wen its like 3rd and 20ish ya kno or end of game so they dont out run my zone..im sayin like during regular play ya kno in the middle of drives in the middle of quarters and games and stuff

If ur gonna play man,you better bring some heat.Sub one of ur DE for a LB/Route him to a yellow zone/Blitz LB from opposite side/Good luck!

on blizing plays when im trying to get to the QB