I think my best score on a 9 hole round by itself was a 32 or 33, but I have shot a 29, 30, and 31 on Kiawah's back 9 during 18 hole rounds. The first was a 63 I shot, maybe as an amateur, that went 34-29. The second was a 65 I shot recently, that went 35-30. And just today I shot a 66 that went 35-31.
Then today I had a round on Bethpage turn to #%%. I was -7 going into... #15. On the back 9 at that point I was -5 through 5. Then... double bogey on 15, composure lost with a bogey on 16. I managed to finish par-birdie -5, but a fantastic back 9 gobbled up by BPB #15.