I'm pretty decent at sparring, but I consistently struggle against power offensive fighters.
Specifically, I mean people who don't respect my punch, have natural powerful punches, and throw a barrage of punches.
When I say they don't respect my punch, I mean that they have a naturally higher pain threshold and can walk through my punches. One fix, I think, is to throw more powerful strikes. When a strike is powerful enough to get them to back up, that usually invites them to throw harder. Since they have naturally powerful punches, this ends up becoming a slugfest, and not a sparring match.
Myself, I prefer to counter punch, slipping and bobbing punches, which isn't necessarily the best approach against people who throw a lot of punches in a row. When I spar them, I throw strikes on the way in, and cover up to get out.
What are other techniques I can employ when sparring offensive fighters?