Bird into Benko [sort of]

Hobbs Gambit

While studying Bird's Opening [and discussing variations], I ran across this offbeat one, which immediately made me think of Greg. I don't think I'd play it, though, and I doubt he would either, but here it is regardless:

Another aggressive [but much rarer] response is 1. … g5?!, the Hobbs Gambit, with play usually continuing 2. fxg5 h6, a sort of mirror-image Benko Gambit. White can simply return the pawn with 3. g6, leaving Black with a weakened king-side after 3. … fxg6. A variant is the Hobbs-Zilbermints Gambit, 1. … h6 intending 2. … g5; against this, White does well with 2. e4 g5 3. d4!

source :: Wikipedia