Compare 2 features for match where spatial join isnt an option.

[FlightDeck]

I have 2 features that I need to compare and if a matching address is found, calculate a field to indicate that a match was found. Likely just "Y" would work in that field to indicate the match. The issue I have is that the Latitude and Longitude aren't even close to matching so a spatial join or near tools do not appear to be an option. Most solutions I have seen for this involve using a join of some kind but in this case I don't have a common field I can reliably use. The only field that might match is the address, but, by the nature of the data set it is going to be iffy. Any suggestions are welcome and appreciated.  

If I the best path forward is to join based on the address is there a "best practice" to help ensure the chances of a match being made or a tool that can help standardize the data?

[DanPatterson]

An attribute join would be appropriate, IF, the addresses in the two files are indeed standardized.  

Have you tried working with a subset of both files to see how different they might be?  (try sorting the address columns and do a visual comparison first)

[TerriSlater1]

XY To Line tool might work on this.  You have to prep the info.  Basically the table needs to have the long/lat of both datasets in one table and XY To Line will create a line between both points which your shape field would be the distance.  If you search Xy To Line, it might give you ideas that might help you utilize the tool.