Calculate a baseball player's batting average. Calculating a baseball player's batting average is not a difficult task at all. A batting average represents the percentage of at bats that result in hits for a particular baseball player. The formula is: That's all there is to it.
To fly under the radar means to act in a way so as to actively avoid detection. It is the opposite of 'in your face'. There is an element of getting away with something but it is not necessarily bad.
(March 2008) In United States aviation, a terminal radar service area (TRSA) is a delimited airspace in which radar and air traffic control services are made available to pilots flying under instrument flight rules or (optionally) visual flight rules for the purposes of maintaining aircraft separation.