The Circuit Board is an obstacle, firstly introduced as the ninth obstacle during Indianapolis finals on American Ninja Warrior 8. It is one of the most complex obstacles ever, challenging competitors both physically and mentally.
Competitors had to use two handles with a ball on each handle (one big, one small) and navigate them through a series of 58 holes, with tracks attached across four panels (the panels were 25 feet in total length), above 15 feet from the water. The balls on the handles could only fit in certain holes.American Ninja Warrior 9, which was very similar from Indianapolis finals, except:
- Some tracks were modified, and
- There were two sets of handles that were placed at the start of the first and third panel (during Indianapolis finals, there was only one set of handles that was placed at the start of the first panel).
A modified version of the Circuit Board (named as the Keylock Hang) appeared as the first obstacle in Stage Three on American Ninja Warrior 8, replacing both Psycho Chainsaw and Doorknob Grasper from the previous season. However, there were significant differences between this obstacle and the Circuit Board:
- Firstly, the Circuit Board used two handles with different size balls on each handle, while the Keylock Hang used two handles with same size cylinders on each handle.
- Secondly, on the Circuit Board, competitors needed to fit the balls into series of holes, while on the Keylock Hang, competitors needed to unlock the handles into series of holes.
- Thirdly, the Keylock Hang had 3 panels, in comparison to 4 panels on the Circuit Board.
- And lastly, on the Keylock Hang, competitors have to jump to a trampoline and grab the bars that lead directly to the obstacle itself, while on the Circuit Board, competitors have to start directly to the obstacle.
Originally, the Keylock Hang was supposed to be the second obstacle in Stage Three on American Ninja Warrior 8, while the Psycho Chainsaw took its place as the first obstacle (seen via Crashing The Course). However, on the last minute, the producers decided to remove the Psycho Chainsaw for unknown reason, and replaced it with a trampoline and two laché bars, as a medium to the Keylock Hang. As the result, the number of obstacles during American Ninja Warrior 8's Stage Three was reduced from 8 to 7.
The Keylock Hang returned on American Ninja Warrior 9, as the second obstacle in Stage Three, with several holes and panels were modified. Also, the bars that lead to the obstacle itself were removed. Despite that, no competitors failed on this obstacle once again (Sean Bryan, Najee Richardson, and Joe Moravsky were able to attempt and complete the obstacle).
- The idea for this obstacle came from a traditional gym peg board, but the horizontal and vertical handholds stick because of friction. So, the producers flipped it upside-down and made more of a mind game out of it.