Cracked up to be

The expression that something or someone is not what they are cracked up to be sounds like modern, informal language but the surprise is that it is neither. It is in fact a perfectly respectable idiom dating from c. 1637. According to the OED, cracked up in this sense, means anything of superior excellence. From this we derive expressions like, crack troops, crack regiments, crack shots etc all of which describe something pre-eminent or first class. For example, a cracking movie or a cracker of a movie meaning an excellent movie derives from the same 17th century source.