With cable TV rerunning our favorite movies at a vicious rate, it is hard to determine whether or not one should give up two hours to the cable gods. Finally, we have a handy formula to help us decide.

Between TBS, TNT, Spike, Bravo, the Hallmark Channel, and every other basic cable outlet padding out their schedules with reaired theatrical releases—not to mention the wonderfully tyranny of HBO, Showtime, and their hydra-headed offerings—there is always a movie to be watched. The problem is, they are almost always movies you've already seen. When is it soon enough to rewatch a movie? And should you be rewatching anything at all? Shouldn't you be ironing your shirts, taking the dog out for a walk, or starting that novel that you claimed you were going to write all those years ago when you graduated college? Should you be staying up watching Role Models on HBO like I did last night? As I discovered, the answer is probably no.

Since you can't be held responsible for such a decision, we now have math on our side to let us know whether or not rewatch a movie on cable. It looks something like this.

This is the basic formula. Caluculate the number of months since the movie's release and multiply that by how good it was. This is based on a factor of three and is a sliding, subjective scale with 0 being absolutely horrible and 3 being one of your favorite movies of all time. Half points are allowed.

This number should be divided first by the number of times you've seen the movie —because honestly, if you've seen it 20 times, you're not going to get that much out of another screening. This number should include the number of times you have seen the movie until the end. That means if you start it late but watch it until the final credits, it counts. If you just tune in for 15 minutes to kill time before another show starts or to catch your favorite bit, don't put that in your tally. We add to this the number of times you've seen it in the past year because that means you're more likely to remember all the details, so you won't need a refresher course. This also gives additional weight to recent, frequent watches.

One that is determined, there are three bonuses, all of which are worth 5 points.

  • Does the movie have commercials or not? If yes, no bonus. If it is uninterrupted, then 5 points.
  • Is there whole or partial nudity of the gender that you enjoy sleeping with? If no, then no bonus. If yes, 5 additional points, you perv.
  • Finally, has your favorite scene happened already? If yes, then no bonus. If no, 5 additional points (and start the microwave popcorn).

The resulting number tells you where this particular movie ranks on the The Cable Rewatchability Index:
0-25: Sorry, it's too soon.
25-50: You should feel guilty for watching it, but probably will.
50-75: Only if you're all caught up on the DVR.
75-100: By all means, enjoy!
100+: Go to the bathroom now, because we know what you're doing for the next two hours.

Let us take the example with our tangle with Role Models last night.

The movie was released 14 months ago x 2.5 for how good it was (I LOLed a bunch)/1 time I saw it in the theater in November 2008 + 0 times since then = 35.

But that is just our base score. Since it was on HBO it gets 5 for having no commercials, another 5 for Stiffler's extended shirtless scene and ass, and another 5 since it was at the beginning and therefore before the awesome battle scene at the end. That puts us at 50. Since I had watched everything on the DVR, I am perfectly excused for watching it.

Of course, this formula is weighted for older movies and movies one hasn't seen in a long time, because it's much more fun to watch and say, "Oh I forgot how funny that line was," instead of mouthing the lines verbatim as they happen. For instance, if one of my old favorites, 1973's Live and Let Die, was on Spike the formula would look like this: 432 X 2/ 5 + 0 = 216. Since it's on Spike and has no nudity, it gets no bonus points, so we'd just have to check to see if the voodoo ceremony at the end had taken place yet or not, for another 5 point bonus. But at 216, it is already a must watch.

This equation also tries to keep you from watching the same movies over and over, like I tend to do whenever Devil Wears Prada comes on. Here is the formula for that: 43 months X 3/ 8 + 2 = 12.9. Even with an extra 5 points for being before the "It's cerulean" scene, it's not time to watch it again.

There are two exceptions to this rule. If you own the movie in question on DVD, then just watch something else. You can see it any time you want thanks to the wonders of the shiny little digital abacus, why aren't you looking for an undiscovered payload of cable gold? Also, this only works for movies you have seen before. If you stumble upon a movie you've never seen, give it a whirl. Even if it's horrible, a new experience is almost always better than a reheated one. With that said, enjoy the cable movies as much as you want, just make sure you're wasting your time with the right ones.

[Image via Steve Rhodes Flickr]