There were 11 power ranks this year, and only 6 players made it onto 6 or more. The graph is of the 6 that did, the x-axis is the power rank (1 is 1st PR of 2010, 2 is 2nd, etc), and the y-axis is 11-position (1st place gets 10, 2nd gets 9, etc). Guess who each line is! If you can, do it without looking at the current PR.
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The top two are obvious, and if you want to "cheat" a little you can look at the current power rank and see who's where.