It's 1v1. The map: Chasms.
You are the UNSC and you're up big time. You control two bases while you've harassed your opponent into just one. You've just attacked the enemy with an army of hornets, and gauss hogs and took out their temple, their hook, and all but two supply depots. They've teched quickly to heavy turrets and that has miraculously allowed them to repel your army thanks to hunters and vampires as well, but the crippling damage has been done.
You take the time to grab some upgrades before you go in for the death blow. You send a scout, but you meet a wall.
His bases is totally backed up with 4 large turrets, and an equally split army of fully upgraded hunters and vampires. And his Brute Chieftan has made it to a two star and also is fully upgraded. They aren't dreaming of an offensive, but as the battle time pushes thirty minutes you want the game to be over EVENTUALLY...
(anti-climatic ending alert)
SO, after another 45 minutes of stalemate you simply resign. "gg turtle" is the msg you send.
Ok, so that's my sad and pathetic true story... so, how do you counter a Covenant turtle, with micro skills better than your own, packing turrets, Vampires, and Hunters?