Is There a Ratio of Naked to Covered Options?

Yeah. The MMer sees it as a single; a short call. He lays it off (covers it) (or) buys half shares (straddle conversion) or some other hedge to flatten his delta.

Regardless of whether it's a synthetic short put or he only sees the short call; the only difference is buying or selling the shares.

 

Thank you for the explanation!

 

To take it one step further, there's the somewhat interesting theory of Cem, that the options are the real underlying.