King: it can always be in the photos.

His butt isn't incredibly weak and has relatively good form. It IS under developed (proper conditioning with tons of trot work could improve it). I'm not sure if it his breed or what. I do think his loin looks a little weak. Again, proper conditioning can make this a relative nonissue.

From the photos, his front end looks much heavier, which gives the appearance of a weaker hind end. Have you put him in dressage? Some solid flatwork will really help him come to fruition.

I'm not an expert ... but I know what I look for in a jumper and that's really about as far as my expertise go, haha. Jumpers is quite different from h/j ... I probably shouldn't have brought it up since you didn't ask about it, haha ... but I know little else (and I don't know much about that either!!!)

If HP is right, and you get him conditioned properly, he'd make a fine h/j. I just worry about his coloring/breed ... which according to HP shouldn't matter.