The Inverter is an obstacle, firstly introduced as part of the Split Decision at the ninth obstacle in the first and second episodes of the semifinals on American Ninja Warrior 13, paired with the Tuning Forks in both two episodes.
This obstacle consisted of two upward horizontal panels, with the first one being placed in a much greater angle, each were supported by a metal structure at each end, which would force the board to lop-side to either left or right, similar to the Wave Runner. However, there were ledges and handles placed in just one side of each board, forcing the competitors to keep their grip when the board rotated.
In order to complete this obstacle:
- Firstly, competitors must grab two sides of the first board, in a similar approach with the Unstable Bridge or Wave Runner.
- Then, they must grab a small ledge placed at the right side of the first board, which would become Cliffhanger-shaped after the rotation
- Next, they must grab a handle placed at the top of the other side of the first board
- After the rotation, competitors must transit to another ledge which also placed at the right side of the second board, however this time they needed to firm the grip when the board rotated down.
- Finally, they must grab back two sides of the second board and traverse to the landing pad. However, it was possible to skip this section, as shown via Max Feinberg's run when he dismounted right from the previous ledge.
During the first semifinal episode, eight of the fifteen competitors who reached the Split Decision chose the Inverter, and it proved to be brutal for those who did so. Only Max Feinberg was able to complete it, while Lance Pekus, Anthony Porter, and Ryan Meeks amongst others failed on it, mostly at the transition to the second board.
During the second episode of semifinals, six of the seven competitors who reached the Split Decision chose the Inverter. This time around, Dan Champagne was the only competitor who failed the obstacle, while the other five competitors (Jay Lewis, Joe Moravsky, Kaden Lebsack, True Becker, and Amir Malik) all completed the obstacle and subsequently the entire semifinal course.