As Terminator Genisys has been one of the major releases this year, let us look back at the Terminator franchise.
It is certainly about travel back in time, so it´s a 3 in the first digit.
Nothing is said about scientific principles explaining the possibility of travelling to the past, so it´s a 0 in the second digit.
Now comes the most intriguing point - what happens with the paradox? I would say it is avoided by first (The Terminator) creating a loop of events closed in itself running between 1984 and 2029: only because the Terminator and Kyle Reese travelled to the past to assassinate and protect John Connor respectively, were the seeds for technology of the machines and John Connor himself planted in 1984. The rest of the franchise tells the story of various attempts by both factions to break that loop in their respective favour, but events always steer back to the original situation, so we could say that from T2, the paradox is again avoided by invoking a mysterious ability of history (the loop) to heal and redirect itself to the its original state. So basically I would set the third digit at a 2.
The actual trip is not depicted in any way, the time travellers just appear (naked) in the chosen moment of the past, so it´s a 0 in the fourth digit.
So provisionally I'd score The Terminator franchise as 302.0, subject of course to review following all your contributions and discussion!