John is a genius

Not only was John able to figure out our fence issues at the Aspen derby, the rest of the lesson was so amazing that it turned the whole week into a win.
I wanted to talk-talk-talk it through to start and he said no, go jump this vertical, and jump it from this tight turn, like you would do in a warm up where you're kind of surprised because someone is cutting you off.  So Duke jumped the teeny vertical, then John made it bigger and he jumped the bigger vertical.  (and cross fired a bit on the far side - we were going right)
I think by then John knew what was what, but he said, ok, now jump this oxer, going left.  And so we headed left and then did EXACTLY what we had done at the show.  So gold star for John and gold star for Duke for doing exactly the same fuck up, and black minus for me for being the only one in the dark.
(This was the only downside to the lesson.  As much as I adore my lessons, I want to be able to ride without John as my Dumbo feather, but I am totally. not. there. yet.)
So what he deduced was that: a) when stressed we revert to our weakness, which for Duke is drifting left.  And I wanted to slap my forehead - yes - we spent like the first four months working on correcting the drift.  And even though John wasn't there to see it, I suddenly had a very vivid recollection of jumping each of the warm up fences way over on the left hand side.  And trying really, really hard to make sure I got Duke right on the corner fence.  And warm up stresses me out.  b) I sat there and passively waited for Duke to jump the fence for me.  Yup.  Just like I did the last couple lessons.  Like a bump on a log, that's me.  c) Duke didn't have enough forward power and then at the last minute I'd put my leg on, and that was too late, he didn't have enough power to take a long push over a training oxer.  He tried, but couldn't.  d)  Duke also doesn't like to fail - he gets mad, and so when we smashed it in the lesson, John had me halt, and kick him hard four times, and then once more for good measure.  This pissed Duke off (although I think he was already mad) but got him revved up in case I went all limp and passive again.  e) John said he also could have been surprised by the width of the oxer, especially if it was built square instead of the back rail a little taller.
So how to fix it?
Well, first is try to ride him without the drift, which is easy to say and hard to do.
Second is that we didn't have many lessons because of California - weather - California, so this is super insightful - I don't jump as often - and clearly not as well - without my regular lessons.  Regular lessons are very very very very important.
Third, ride outside bend, then inside bend, then use my left leg (going right) to push him over to the right.  LOOK RIGHT.  Look up and over the fence - look at the right standard on the next fence or the letter on the center of the arena.  If I need to, push him forward on the long side before we start the turn to the right.
Fourth, when I feel him fade several strides out, PUT MY LEGS ON.  The very last fence this worked like a charm.
John said that this showed why riding him novice last year, as much as I wanted to keep going training, was for the best.  Thanks to that, I know Duke, and I trust him, and this would have been (my words) a disaster if it had happened right after I got him.  We both would have lost confidence in each other.
John also said the drift is a little easier to see on the ground, and showed me the strides to the oxer, where two strides out and one stride out we were ok, but then we jigged to the left for take off.
So the exercises we did, after the crash?
First we did a vertical-vertical line in six strides.  Then again.  Then in five strides.  Then back to six strides.
Then we got back on the rail and then angled the second vertical only (from left to right - so left shoulder on rail, jumping towards the center of the arena; i.e. butt at 7 pm, head facing 2 pm).  Then rode it straight down the center again.
Then we changed directions.  It was MUCH easier to do on the left lead - making the left turn in.
Then we rode the oxer.  Then we rode the oxer on an angled line (from the center to the wall, so jumping it from 7 pm to 2 pm).  Then we rode the oxer the angled line again, then straight.
John says do this in the warm up (fifth), because then Duke isn't sure whether I'm going to angle the fence until we're right up on it, and this helps keep him from drifting left.
It was pretty cool we could do the six strides, five strides exercise, and really interesting the difference between making the right hand turn and the left hand turn.  I think what is missing on the right hand turn is left leg.  That is my weaker leg, and I think it isn't holding the outside of the turn as well as it should.
John is in Montana this weekend, so no dressage lesson, and at Tulip Springs next Saturday, and he said don't start riding in the draw reins again without him.  He said the next California is Twin Rivers, so that's when I'll get truck and trailer maintenance (and tires and washing) done for the spring.  He said to check the rules, but we can maybe try to do the Training 3 day at Rebecca (in which case, do hock injections about 6 weeks before, not now). (!!!!!)