17 is one of my favourite greens, too, Mick. It's simply an extension of the fairway, bascially separated into three distinct 'cupping areas' at front, back-left and back-right, by gentle terraces. And, of course, there's that large knob in the centre of the green! Between the subgrade and the final grade that knob evolved into a very prominent feature, which makes it difficult to putt from one section of the green to another, doesn't it.
The golfer's objective, ideally, is to hit the correct section of the green in order to have a decent chance to two-putt.
We created that large depression which starts about 100 yards short of the green, and runs parallel to the hole up to the left side of the putting surface. I spent about a week on a D-6 widening a narrow ditch that was there when we showed up.
The 'trench bunker' benched into the right side of that depression, just short of the green, was inspired by some similar bunkers Rod saw on a visit to Pine Valley just before we started construction at Blackhawk (I'm thinking, left side and short of 13 green at PV, down in that similar depression/valley there).
Back to 17 green, notice that it's tilted from right to left as well, with a slight Redan 'kicker bank' type feature at front right of the putting surface. 17's a long par 4, 445 yards or so played slightly uphill, into the prevailing wind. The orientation and slope of the green, combined with the 'kicker bank' we created is intended to allow smarter golfers to play a low draw from a long distance around the aforementioned depression that will (theoretically) 'kick' left and take the slope down to a back-left hole location.
This is (potentially) a great match-play hole, late in the round, because a better golfer who's hit a decent drive will probably be suckered into flying it right at a back-left hole location, which is guarded by another deep bunker cut into the upslope of the depression, immediately adjacent to the putting surface. It's one of the more heavily treed areas on the course, so it's sometimes difficult to feel that prevailing wind, into you, which results in underclubbing.
A classically-inspired golf architect (like Rod Whitman) would like nothing more than to see a keen, comparatively short-hitter out smart a stronger opponent by figuring out the strategy of the hole and executing the proper shot!
Perhaps we overthink these things