The franchise for the Phillies has been around a long time. The team started of course in 1883 and since then, the Phillies have only played the Chicago White Sox a total of 9 times. So, the series that is starting this afternoon and then the night game of the day/night doubleheader will be less than a dozen times that these two teams will have played one another.
The Phils have a winning record of 5-4 for the lifetime series against the White Sox.
Interleague play has brought both the American and National Leagues much closer since it started back in 1997. Now more than ever, the two leagues are starting to play each other more, over the course of the long 162 game schedule.
The only other team that the Phillies have played less times against has been the LA Angels, the two teams have met only 6 times in the history of the both franchises . For the Phillies it's been a tough team to play, they are 1-5 lifetime against the Angels.
Here's a graphic of the Phillies Head to Head record against all the teams in baseball since 1901: (sorted by the teams the Phils have played the least) Thanks to Baseball-Reference.com