You need to earn a Gold Medal on each of the 25 levels of Pursuit mode. Pursuit mode can be selected by picking Single-Player from the Main Menu. Make sure to disable the medium and hard question packs.
In this mode, you move across the board towards a finishing tile by answering questions. Depending on how quickly you answer the questions, you can move anywhere between 1 and 6 spaces per turn. Gold Medals require you to get from one end of the board to the other within a certain number of turns. Basically, as long as you use the trick mentioned in "Absolute Cheater or Genius" you will have no trouble. Getting Gold Medals is easy as long as you take the shortest path to the end of the level, do not miss any questions and answer them quickly to earn 6 moves. There are power-up tiles (have a star on them) that can help you a little, but do not go out of your way to land on one. They are not worth it. You can answer questions wrong and still get Gold, but not too many. Usually 1 or 2 is fine, but some levels have no margin for error. If you miss one early in a level, it may just be best to restart.
This is the achievement that will take you the longest in the game to earn. You will have to answer over 200 questions, even if you get Gold Medals on your first try of every level.