Impact Calculus is Impact Comparison

This is a concept that seems simple, and yet it's one that a huge proportion of debaters get wrong on a regular basis.

The way that most people deploy the concepts of timeframe, magnitude, and probability is hopelessly inept.  Most attempts sounds something like "Our impact has a huge magnitude - it ends in a war!  And it has huge probability - we made a link argument!  And it happens soon!  We win timeframe!"

These arguments are meaningless, or at least, irrelevant in the context of impact calculus, because they are not actually comparing one impact to another.  It is not sufficient to demonstrate that your impact is very big, it is essential to demonstrate that your impact is bigger than a different impact in the round.  For example:

"Global Warming outweighs their small nuclear war on magnitude - if allowed to go on, warming will make the planet uninhabitable for all humans, which means extinction, whereas estimates of even the worst nuclear wars suggest that about 5% of the population would be alive after them."

The same thing goes with probability.  If you are making an argument about probability, you are not trying to say that your impact is definitely going to happen.  Instead, you are comparing the way the debate has shaken down on the link level on a couple of different positions.  For example:

"The disad outweighs advantage 1 on probability - they made exactly zero arguments on the link level of our d/a, but we have two strong defensive arguments on the link.  Even if you feel like they have decent responses to those defensive arguments, you should still be treating their aff as only having some chance of solving their impacts, which is not going to outweigh a 100% risk of the d/a."

Finally, timeframe.  This is probably the most botched aspect of impact calculus in the rounds I see.  Not only do people fail to compare the timeframe of two different positions, they fail to explain the relevance of timeframe in the debate.  And without this sort of explanation, timeframe is totally irrelevant.  Think about it - 1 million people dying today is pretty much equivalent to 1 million people dying 6 months from now, and you'd sooner take a hangnail today than a bullet in the head a week from now.  Timeframe is only relevant insofar as the speedier impacts change the way that other positions in the debate would operate.

The classic example of this situation would be an alternative energy aff that claims a warming impact against an econ d/a that ends in immediate economic collapse.

"And, the d/a outweighs on timeframe - a market panic will ensue within the next month, which is far sooner than alternative energy will be developed even under the most optimistic forecasts of the plan.  When the economy goes under, all the alternative energy companies will go out of business, which means that the aff won't be able to solve anything."

You'll notice that this sounds a lot like "d/a turns the case."  No kidding.  In a real sense, the tools of impact calculus are not "magnitude, probability, and timeframe."  They are "magnitude, probability, and turns the case/da." 

But this is a bit of a ramble.  The most important thing to notice about all of these examples is that they involve explicit comparisons between different impacts and link stories.  If you are not making an explicit comparison, you are not doing impact calculus.  Simple as that.