When teaching a new skill, but especially when teaching stay or doing distraction training, there's an inclination to increase the difficulty after each successful rep.

If your pup holds a 30-second stay, you're inclined to ask for a 45-second stay on the next rep. If your pup can hold his place when you drop a carrot on the ground, you're inclined to ask him to hold his place when you drop a piece of chicken.

Somewhat counter-intuitively, this can actually hinder your progress. It makes sense if you remember that these are training games.

If you're playing a game that only gets harder every time you win, at some point it gets so hard that it stops being fun. If there's no option to go back and play the easy rounds, you might just quit playing altogether or at the very least, you'll stop trying to win.

The same is true for your dog. It's frustrating to constantly be asked to perform at your maximum ability. Imagine what your dog is thinking "Gosh, this is hard. Oh wow, this just got even harder. Are you kidding me? This is impossible. Ok, it's not worth it anymore. I'm out."

So what's the answer? Easy. Mix it up.

As you're increasing the difficulty, mix in easy reps. Keep your pup guessing to keep him engaged. The short reps remind him why it's fun. The long reps make him appreciate the short reps. Good game design is unpredictable, which is exactly what your training sessions should be.