Also: Didn't Doomguy lose to the chief in one of those ScrewAttack Deathbattles?
Yeah but it's complete nonsense. Chief's shield can't withstand a full BFG blast (to be fair, not much can). Even if it saved him from the direct impact (being generous here but it's reasonable enoough) he'd still get splattered by the tracer rays that follow immediately after.
The bubble shield protected him, and if the bubble shield can stop a wraith mortar, which is also plasma, then it can stop the BFG.
There are many worlds, but they all share the same sky, one sky one wish. GT and PSN: StealthyVlad