St Augustine/Bermuda/Centipede?!?

Yeah, looks like St Aug. and Bermuda. What are you looking to do with it? There's really nothing out there to eliminate the Bermuda without killing the St Aug. If it looks good to you, I'd just keep what you got going. Or you could slowly transition to a full Bermuda lawn (as long as your property has plenty of sunlight).

It's also hard to have both grasses look their best since Bermuda likes to be 1" or under and St. Aug likes 3.5" or higher

I'd just keep going with what you have going then. Looking great from the street is all most of us care about. :thumbup:

Are you somewhere near a golf course? You'd be amazed how that Bermuda seed can travel and take hold. Or have you used your mower on a yard that has Bermuda? It can easily spread that way too.