In my main video, I mentioned something called the shortest split-line method. I really had to zoom past that because of time constraints, but it's a very interesting way of dividing up voters into boundaries, into different districts. So I wanted to spend a little bit more time going into depth with it here. So this is the sample population I used in the main gerrymandering video. There are about 40 voters here and I wanted to divide them up into

eight different groups. Now when you have an easy number it's a pretty simple thing to do.

You find the line that divides them into two equally populous groups and use the

shortest line if you have multiple lines that will do the same thing. There are 20

voters on the left and there's 20 voters on the right. Then you take each of those

two groups and you do the same thing again. You find the shortest line that will divide the two populations

into equal sized groups. So now there's 10 in each group. And ultimately we want eight voting

ranges here. So we divide them one more time. And you end up with eight equally sized ranges,

each with five votes. And that's the basics of the shortest split line method.

Just always use the shortest line you can to divide the two groups.

But the question that naturally comes up is what if you have an odd number of districts?

If you want to divide them into seven groups instead of into eight groups.

This is where the cleverness of the shortest split line method comes up.

If you take seven divided by two, you don't get a round number, you get 3.5. But what you do is you take that 3.5 and you round it up to get 4 and down to get 3. And this tells you the ratio that you want to draw the line at for the population. So you want to draw a line that divides the population into a 4-3 ratio.

For every 4-voters in one group, you want 3 voters in the other group.

So as best I can tell, this is the shortest line that will divide this population of voters into a 4-3 ratio.

Let's just double check. There's 24 voters on the left. There are 18 voters on the right.

24 divided by 18 gives us 1.3, and 4 divided

by 3 gives us 1.3.

We've drawn this line in the right spot.

The next step is to take that ratio, that 4-3 ratio, and that actually tells you how many districts

you then want to divide each of these separate groups into.

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