The maximum jump height of Preferred is 20 inches regardless of the height of the dog which is why we "prefer" it for Rotties where they would have to jump 24 in Regular Classes. Less jarring of the joints. Working dogs are just too heavy to handle all that impact from the 24-inch jumps.

That Boxer can leap! Reminds me of our boy JAG who in his prime could clear the 20-inch jump by 6 inches or more . Now, that's fun!

Jim