Mike,
I'm not sure a crowbar will work. We may need dynamite.
The crowbar is the workmanlike traditional approach. Cut back supply, grow demand, have a little bad weather. But to have a big event, a black swan, may take the geopolitical activity;. Maybe it's not dynamite it's gunpowder.
Al Kluis is optimistic. It usually rallied from Dec to Jul. OK. The "out of storage" bushels are in the pipeline and now basis can improve. OK. The funds are short (so they have to buy back sometime - don't they? Don't they? Don't they? What if we grow more corn in '18. Maybe we'll see a new definition of record short.)
North Dakota may get tired of weak basis. What will they grow? Wheat? Are you laughing yet? That corn is headed to the west coast to Asia, bad basis be damned. North Dakota may not like a weak basis but you aren't going to try to persuade me they are going back to wheat, are you? Soybeans, yes.
A 20-30% rally means corn from $3.60 to $4.50. Most of us would be delighted to see $4.50. More than that? Better hope the North Koreans don't start slinging ICBMs. The price of corn might go up and I might not have any to sell. 
I'll plan to market into $4 corn have a plan if it gets higher. The problem with black swans is they often don't send any signals ahead of their appearance. I hope I don't get whipsawed by one in '18.
I think corn is more of a "good-bye" than a "good buy", to "pry it off the floor" let`s be careful we don`t fall through the floor into the basement 
Now with the 2B+ carry it has the same effect as the old 4BB carry, Lord help us when we do get back to that old carry. A 1987 drought wouldn`t be as devastating with today`s hybrids, poor countries sell us more stuff, but they can`t afford to buy more grain and oil seed in return.
We`ve got a John Deere low a first half cash rents coming due right around the corner, farmers being the only "long" hot potato holders will have to be dropping it in some fashion or another in a couple months. If you`re a buyer, sit and wait and take it off the clearance rack after Christmas or Ground Hog Day.
Fertilizer tenders met themselves coming and going, tillers were burying pipe in the ground, coops run out of gas even after it went up $100/ton don`t hear anyone screaming "uncle" yet.
