In your mind, what average PGA Tour sand save stat would satisfy you that bunkers are presenting enough challenge? 20%? 30%? 40?
David,
That's one of those questions that affects how people think about design. If my answer is 25%, and the pro's encounter a bunker that the save % is only 10, someone is going to say that bunker is unfair, or too difficult, which leads to that bunker being changed for the sake of satisfying a statistic. Which is likely to lead to bland design.
So, I would say it should be somewhere between 5% and 75%.....
My point isn't about raising or lowering a statistic. It's as much about variability, and unique presentations based on a courses locale, and using local materials, etc, rather than the pursuit of uniformity and watching the pros play the same shot week after week, no matter how far they've traveled. And, subsequently, how design might be affected by that variability week to week....