OK, so we are now onto the great RBI vs RBI's debate, and fella's, there is only one right answer here?: R'sBI.
Runs is plural, always has been, always will be. We are not talking intestinal distress here, but moving multiple runners across home plate over time.
An argument may be made to move the possessive to the end, after In, but, for consistency, I prefer it remain where it rightfully belongs, proximate to the noun it so modifies, hence, R's it is. I have dutifully notified MLB of the same and expect full compliance forthrightly, in about the same time frame as the sticky stuff disappears from pitching gloves.