I think the phrase is actually "3rd times a charm", but for me and domains its the 6th. My 6th domain I purchased was http://www.dsromcards.com.
It doesn't even have anything on it, but its ranked 4th for "ds rom cards" hah. So, I'm unbelievably excited to actually start monetizing it.
My point with this was.....the impact of choosing an exact phrase domain is incredible. Glad I found out early on.