Do you run an 800 all out? You might, if you are slow and just trying to keep contact with the leaders.
It was mentioned before that pure sprinters won't run the 200 all out. Neither this guy nor me when I ran the 200 are pure sprinters. We are discussing middle distance runners filling a lane in a sprint event. If you go all out just to maintain contact with the back, those last 50 meters are going to hurt. The last 200 of an 800 is going to hurt anyway if you do it right, whether or not the race is tactical. It is the nature of the beast.