The Circuit Board is an obstacle, firstly introduced as the ninth obstacle in 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. Eight competitors reached this obstacle, and five of them completed it (Ethan Swanson, Ian Dory, Brian Arnold, Jake Murray, and Adam Arnold).The Circuit Board returned as the ninth obstacle in Daytona Beach finals on American Ninja Warrior 9, which was very similar from Indianapolis finals, except some tracks were modified, and a set of handles was placed at the start of the first and third panel (in Indianapolis finals, a set of handles was only placed at the start of the first panel). Once again, eight competitors reached this obstacle, but only four of them completed it (JJ Woods, Sean Darling-Hammond, Jessie Graff, and Drew Drechsel).
Keylock HangA modified version of this obstacle, named the Keylock Hang, was placed as the first obstacle in Stage Three on American Ninja Warrior 8, replacing both Psycho Chainsaw and Doorknob Grasper from last season. 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, in the Circuit Board, competitors needed to fit the balls into series of holes, while in the Keylock Hang, competitors needed to unlock the handles into series of holes. And finally, the Keylock Hang had 3 panels, in comparison to 4 panels in the Circuit Board. Only Drew Drechsel and Daniel Gil attempted and completed this 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.