Which course has the most difficult greens?

Jack's Memorial looked like a mini-Major with a winning score of only -9.  A more typical winning score on Tour is -12 to -18.   I have not played Muirfield Village (...never get invited anywhere!) but I have walked/run the course (long story).  In my opinion, it is a very hard golf course - streams meander thru and around almost every hole; the woods loom large, deep and dark; and the green complexes are severe.  Remember when Jack added special rakes that created deep furrows in the sand traps?  How hard is it?  The Course rating/Slope system does a fairly good job of displaying the relative difficulty and Muirfield "Memorial" tees are rated 76.9/153, which is up there - 4.9 strokes above the 72 par for the scratch golfer.  

Watching the event, I wondered "OK, I get the difficulty of the course but what about the greens alone?  There must be a way to judge the most difficult greens on Tour."  As my readers know, I am a big fan of the Tour's new Strokes Gained Putting stat.  I am certain that the answer lies in this data but is not readily available to "outsiders" because the raw data is "normalized" each week so that all we see is how players relate to the average of the entire field for that event.  The average "Strokes Lost" to the Tour's performance model each week would clearly reveal the relative difficulty of the greens at each venue.  Until I can get this data, is there another way?

How about the relative frequency of 3-putts for the field?  For this, I looked at an old, traditional Tour stat - 3-Putt Avoidance:  The percent of time 3 or more putts were taken for a hole (total 3 and 4-putts divided by the total holes played).  I looked at all 2012 Tour events (thru Memorial) and found the following:

• The average of all 22 events:  3.31 (2.38 3-Putts per 72 holes played)
• Easiest greens:  Doral Blue Monster @ 1.95 (1.40 3-Putts per 72 holes played). 
• Most difficult:  Kapalua Plantation @ 5.04 (3.62 3-Putts per 72 holes played)

Other difficult greens:

• Augusta National:  4.88 (3.51 3-Putts per 72 holes)
• Quail Hollow:  4.33
• TPC Sawgrass:  4.32

Other easy greens:

• Harbor Town:  2.04 (1.46 3-Putts per 72 holes)
• Waialea CC:  2.19

To add some perspective on 3-Putt performance, the graph above compares the average # of 3-Putts per round for the PGA Tour Winners (2012) and Tour average to an array of handicap levels.