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.
The radar gets its name from the distinctive folding mast which when deployed allows the radar to see over nearby terrain features such as trees, extending its effective range against low-level air targets. The first systems were produced in 1977.