Found this interesting trivia on pgatour.com - too lazy to post the link No one has shot 4 rounds in the 60's at the Masters. All other majors and even the TPC (the 5th major for some) has all had somebody shot 4 sub 70 rounds. I found that interesting because The Masters seemingly has the 'easiest' layout - 3 or 4 reachable par 5's, minimal rough and fairly benign bunkering. The winner usually is between -8 to -13, lower scores you see in the Open and sometimes the PGA, yet no one has broke 70 every day.

Shows you don't have to trick up a course, grow the rough a foot thick, let greens fry in the sun, etc to challenge the Tour players.