Which is a simple sentence?

 - First, Leo planted the geraniums in a clay pot, and then he placed the pot on a sunny windowsill in his kitchen.
 - Babe Ruth hit 714 home runs during his baseball career but struck out 1,330 times.
The second sentence is the simple sentence. It is a single independent clause.
Babe Ruth hit 714 home runs during his baseball career but struck out 1,330 times.