Nut Clip

Nut Clip is a moon clip that takes place within the Wooded Kingdom tunnel, using the Tucked Away Inside the Tunnel nut moon. It allows Mario to reach an out-of-bounds area that enables the Behind the Rock Wall moon to be collected without the use of the Sherm enemies.

Execution

Just like any other moon clip, Nut Clip involves tilting Mario's hitbox into the wall behind the moon by backflipping and then throwing Cappy into the wall just as the moon becomes solid.

Since the nut takes three hits to break, it must first be hit twice to prepare the trick.
Position Mario just below the nut, facing toward the camera.
Backflip once to break the nut, then backflip again to prepare the moon clip. Perform a cap throw in the direction of the wall just as the moon becomes solid. The timing for this trick can be achieved by mentally counting to five in rapid succession: performing backflips on 1 and 4, and throwing Cappy on 5.

Speedrun usage

Any%

Using Nut Clip in an Any% speedrun results in a complete route change for the Wooded Kingdom. After Nut Clip is performed, Mario can continue to climb the out-of-bounds areas to reach Behind the Rock Wall and The Nut that Grew on the Tall Fence. Mario can then drop down to collect Climb the Cliff to Get the Nut, and then proceed to the moon in the Red Maze. After that, the route is the same as the beginner route until reaching the top of Sky Garden Tower, at which point the player can drop back down to the mainland to collect the three remaining moons.

If the player is inexperienced with the out-of-bounds movement following Nut Clip, but skilled at the clip itself, the clip can simply be used to bypass the gate. This still saves time over pulling the lever to open the gate normally.

World Peace

Instead of resulting in a new route, Nut Clip is used in the World Peace category simply as a way to skip the lever to reach the Climb the Cliff to Get the Nut moon. The clip saves much less time in this category than it does in Any%.

Advanced Nut Clip Route

Nut Clip secretly has ways to save time not only by performing it but its movement and certain route take.

After collecting the moon from the shop turn your camera to the left.
Spinpound and keep rolling and before passing the tree on your left initiate a roll cancel where cappy hits the tree, then do a cappy return jump followed by a triple jump.
Aerial cap jump (if necessary) wall jump and dive followed by another spinpound and a shirane cap bounce moving forward, roll boost to the Uproot and spinthrow roll cancel to capture it. Collect the Atop the Tall Tree moon and then start making your way to the nut clip section.
Keep roll boosting and then if you happen to have enough room you can roll cancel cappy return jump by a triple jump to the center and dive.
Backflip and throw cappy and when Mario dives on cappy, turn around and upthrow hitting the nut once, jump to hit the nut again and then do the moon clip sequence.
After clipping out of bounds you need at least enough room to backflip and shirane bounce on cappy to get to the open ledge of ground.
You can either longjump and grab the moon (however it is too risky because you can get stuck in the box and warp out) or do it the standard way which dosen't save enough time.
Once grabbing the moon you carefully want to time your aerial cap jump to the right and wall jump holding down on the analog stick and dive on the ground resulting to keep roll boosting to the ramp.
When running up the ramp you at least want to press the jump button 13 or so to get the extra final jump.
If you get the extra final jump instead of wall jumping aerial cap jump and upthrow then dive on the railing resulting in a roll boost.
The final part (which is the trickiest) requires a roll cancel cappy return jump on the left side of the railing which requires four things:

        *You need enough speed in order to vector the jump to the moon
        *The analog stick needs to be held up slightly forward in order to gain speed.
        *You have to dive at the right time or it results as a bonk or an overshot to the left or right.
        *Lastly you need to roll after the timed dive (don't roll boost) and spinpound when the roll animation ends plus it should be close to the edge.

If these tricks were done correctly then you can collect The Nut that Grew on the Tall Fence moon without a problem.