Okay, for those who don't understand the value of a per capita based ranking...
Imagine a real-life game of Where's Waldo. You have to find Waldo in a big three-story house with many rooms. Actually, we're gonna compare finding Waldo in two different houses, next door to each other.
In the first house, there are a TON of people in every room. You can't just glance in the door of the room and be assured you'll see Waldo, even in his red-and-white striped shirt, because he could be hidden behind other people or sitting on the chair in the far corner, that sort of thing. So you have to go through each room and look closely.
In the second house, there are still lots of people, but they're only in half the rooms. You have to look just as hard in the crowded rooms, but can just glance in the empty or near-empty ones. So your search can go almost twice as fast.
Thing is, there are two Waldos in the first house, and just one Waldo in the second. So the reward for "finding Waldo" is roughly equivalent between both houses. Law of averages says it will take roughly the same amount of effort to find a Waldo, whichever house you choose.
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Waldo is a star football player, the houses are states, and the rooms are high schools. One state has twice the population of the other, and twice the raw number of great players. But it also has twice as many high schools you have to visit to find those great players. So the effort is roughly equal.
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If every state on that map had the same value, were the same shade of pink, that'd be the end of the story. But it's not. Because there are actually slightly more Waldos per capita in some houses than in others. This per capita chart takes all of the variance mentioned above into account, and shows where you might find 1.5 Waldos (Tennessee), versus just 1.0 Waldos (Ohio) for the same amount of effort.
That means a recruiter is actually more efficient looking for talent in the states with higher per capita talent than the ones that are lower...even if the lower states have a bigger total number of great players.
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So that's why it's a very useful metric.
Hope this helps.