You might have seen images of this map, which I've taken from a post by Richard Engel, NBC News Chief Foreign Correspondent. It's a map of the US military's counter insurgency strategy in Afghanistan.
(Click on the image to see it full size.)
What do you do when you are trying to illustrate a complex idea in a single graph?
Richard Engel says, "The slide is undoubtedly overwhelming. For some military commanders, the slide is genius, an attempt to show how all things in war – from media bias to ethnic/tribal rivalries – are interconnected and must be taken into consideration. It represents a new approach to war fighting, looking beyond simply killing enemy fighters. It underscores what those fighting wars have long known, that everything matters."
A slide like this could actually be used as a humorous opening to a presentation, were the subject matter different. The complexity is both funny and tragic in its current context.
So I might show this graph to illustrate the complex idea, but then I would break it down into understandable chunks which, in this case, would probably take no less than 500 slides.
I haven't sat in on the Joint Chiefs of Staff's meetings to discuss the war strategy, so for all I know, they have another 500 slides that break this down.
But to try to tell the whole story on one slide -- in any presentation -- is generally futile.
Stick with one idea per slide. And if you have 500 slides at the end of the day, maybe you are trying to express too many ideas in one presentation!