Boy what came first the chicken or the egg! 

There are so many factors involved here do you hit the ball high or low, draw or fade, technically a high fade should carry further than a lower draw so on a down hill shot it would drop more vertically and stop faster as opposed to the draw which with a less steep angel of approach should land and release more. I don't factor elevation changes until 30 feet or more at which time I add or subtract one club then plus or minus one for each additional 15 feet thereafter. That's just my approach to severe elevation changes it seems to work well for me but on these tricky distance shots I always aim for the middle of the green and play a draw to back pins and a fade to front ones assuming the lie is good and it doesn't bring a lake or something into play.

Guesswork and good judgement is one of the most compelling things I love about our great game good luck.

David

I agree with David.  Elevation changes are all over my course and I only make adjustments for major changes. 

I would say an elevation or depression of 20-30 feet is one club more or less.  I have one par 3 that is 175 downhill and I use a 4H and there is another that is 175 uphill and I use a 3 wood.   For a pitch shot that is ac tually playing 25 yards and the green is above the reach of my arm, I treat it as a 40 yard shot.  I know if the green is 120 yards away and it is slightly above my head, I'll hit an 8 iron (normal flat distance on my 8 iron is 130-135).

I would say an elevation or depression of 20-30 feet is one club more or less.  I have one par 3 that is 175 downhill and I use a 4H and there is another that is 175 uphill and I use a 3 wood.   For a pitch shot that is ac tually playing 25 yards and the green is above the reach of my arm, I treat it as a 40 yard shot.  I know if the green is 120 yards away and it is slightly above my head, I'll hit an 8 iron (normal flat distance on my 8 iron is 130-135).

Agree with Carl... wind in your face hurts way more then wind at your back helps.  I find that I need to play holes with drastic elevations changes 2 or 3 times at a particular course before really feeling the distance and club selection. I do love a picturesque downhill par 3 though.

I also agree with Carl on the wind.  That can stop the ball dead or help it.  A headwind, regardless of whether the shot is downhill or uphill will kill a high trajectory shot.   A tailwind will aid a high trajectory shot.  You may find yourself doing a pitch shot with a 6H on a 140 yard downhill par  3 instead of a 9 iron (assuming one hits an 8 iron 140 yards on a flat surface with no wind).