RPM is the acronym used for revolutions per minute. It measures the number of revolutions completed in one minute around a fixed axis, giving the speed of a mechanical component. It is commonly used to describe the performance of automobile engines.
Like most ballparks built from the 1990s onward, Safeco Field is a 'retro-modern' style ballpark that incorporates many of the features of ballparks built in the 1950s and earlier with modern amenities.
Connie Mack Stadium, named after the long time manager of the Philadelphia Athletics, was named that in 1953. Previously it was called Shibe Park after Ben Shibe, an A's stockholder and baseball manufacturer. This was the first concrete and steel park built. It paved the way for Fenway Park, Wrigley Field, and others.