10 Things You Didn't Know About The Millennium Falcon
3. The Whole Kessel Run Thing
The Millennium Falcon made the Kessel Run in under twelve parsecs. So claims Han Solo in A New Hope, and the nerds of the world haven't let him forget it. A 'parsec' is a measure of distance, not time, so Han's boast doesn't seem to make a lot of sense. Various theories have tried to work out just what the whole Kessel Run thing meant.
One possibility is that Han was just using fancy space words to show off and didn't know what he was talking about. The original script for A New Hope suggested this was the case. Another is that he was deliberately using the wrong terminology to see if Ben Kenobi knew anything about space travel, to work out how much he could overcharge the old man for a trip to Alderaan.
The Star Wars Legends canon includes detailed descriptions of the Kessel Run, which involved skirting around a bunch of black holes. The closer a pilot dared get to the black holes, the shorter the route was, and hence Han's bucket of bolts made the route as short as possible (twelve parsecs to be exact). George Lucas' own explanation was that the Millennium Falcon's upgraded navigational computer meant it could calculate the most direct hyperspace routes between two points, and hence '12 parsecs' was indeed a measure of its speed and efficiency when travelling.