For @appenzellerlouis who was nice enough to ask and anyone else curious how I approached teaching the stacking the ring(s) trick.
The short answer is free shaping.
The detailed answer is this.
I teach in short sessions and there are three rounds in a session. I did this with two dogs so the breakdown was each dog gets a turn or round lasting anywhere from one to three minutes and then the other dog goes. If you're only working with one dog I still recommend giving them a break in between rounds. This helps keep down frustration.
The first thing I did was teach the dogs to put a ball in a bucket. This introduces the concept of having the objects interact in a way that allowed them to be successful more easily. It's way simpler to drop a ball in a bucket than to get the ring on the base correctly.
I taught both behaviors through free shaping. For anyone not familiar it's clicking/marking as the dog gets closer to the end goal. But you only click/mark for new progress. Meaning once a dog has gotten to picking up the object, there isn't a reward for just putting their mouth on it.
Look at ball/ring - click
Put mouth on ball/ring - click
Pick up ball/ring - click
Pick up ball/ring and drop it near the bucket/base - click
Pick up ball/ring and drop it so that it touches the bucket/base - click
Pick up ball/ring and drop it in the bucket/on the base - rapid clicks and multiple rewards to signal the dog successfully figured it out.
For the ring, I was more generous with rewarding the picking up the ring and lifting it up high enough to hit the top of the base even if they didn't successfully get it on the base because that requires more precision and I wanted to reward the effort.
At the end of the round I moved up the first requirement that I'll mark and reward for. Meaning if after the first round the dog was consistently picking up the object I won't reward just looking at it in the next round.
Here's the same clip, just played at normal speed and without the music. Faye was already successfully picking up the ring and dropping it near the base. So my starting criteria was picking up the ring and dropping it close enough/high enough to the top of the base to hit it.
I like teaching these tricks through free shaping because it provides great mental exercise for the dog. They really need to think through what's being rewarded.
It's important to keep this type of training short and sweet. The first round Forte was presented with the ring and base was maybe a minute long because he kept stepping on the ring and picking up the base. Not at all moving in the right direction. So I sent him back to his bed and started the next round with Faye.
As a side note, I always reward the dog at the end of their round once they've returned to their bed.
When it comes to adding difficulty, two toys in the bucket or two rings on the stack, I want to be sure they have the first part down. This means the dog should successfully get the behavior in all three rounds.
Hopefully this (mostly) makes sense. If anyone has questions I'm happy to answer them!