Let me break it down like this. I ran Maintenance at golf courses for about 15 years before I started my business. I have college degrees in Horticulture. I've been to TPC Sawgrass and Augusta National as well as other top notch golf courses. My little local hometown course that i've literally played 1000's of times isnt even a slightly the same as these courses pga players play. If you're a really good golfer that shoots 76-78 at your city of whatever the fuck golf course you wouldn't keep it under 95 at a real pga course set up the way the pga or USGA sets a course up. No fucking way. The yardage is only a small part of it.
The Sony open in Hawaii is generally regarded as one of the easier courses that pga players play. This year the winner of that tourney was -27 and just played safe on day 4. Spieth was -19 and shot 65, 67, 66. 63 in the 4 rounds, and that course is still miles harder then anything 99% of us play on any given weekend with our buddies. If Spieth comes and plays my local sandridge golf club he shoots under 60. No question in my mind. If me and Spieth are both standing 140 yards from the pin and i get 3 shots to his 1 then he probably puts his shot inside any of mine 75% of the time atleast, and i'm a decent golfer. You guys that think the extra distance is a huge advantage/ factor, its not. The 3 shots would be a much bigger advantage but it still wouldn't matter. He hits the ball alot further and straighter then any of us. The extra distance is basically negated after the drive and he is now standing in the fwy holding a higher numbered iron then we are. If it hit a ball 270 off the tee, he hits one 310 and now i'm holding a 7 iron into the green and he is holding a 9 iron.
I played the Chaska Town Course the day after the US Amateur Open was played their. They left the rough and pins in the exact same spot. I normally shot about 75 at the time. I think I shot closer to 90 that day....it was over 10 strokes harder. If you ended up in the rough...chipping it close was next to impossible...so instead of an up and down....it was taking me 3 shots and occasionally 4 shots. If you missed the fairways the ability to hit the greens was much more difficult. By the end of the day I was a beat down golfer and frustrated. But if I had 3 drives....on 14 holes....I most likely would not have been in the rough. If I had 3 shots at the green...once again I would not have a difficult chip that costs me a stroke.
The difficulty of course would effect the outcome. I think the harder the course the bigger the advantage to the golfer in many respects. If the rough is thick and a huge penalty....hitting 3 drives to having to live with just one drive....the advantage would be to the golfer. If the course has hazards that cost you for poor driving the....hitting 3 drives is advantageous. The weakest part of his game is his driving. He only hits 6 of 10 fairways.
If you are both sitting in the middle of the fairway and even close in yardage. He is going to have a higher number club and the advantage turns to him. On a longer course like I had stated where yardage difference is significant between the tips and the whites you might be hitting the same club....he just hits his 30 yards further. Now it is 3 shots to one. He is not going to hit it closer every time. How many times yesterday was he inside of 160 and was 50 feet or more from the pin? Quite a few.
His biggest strength is his putting. Nailed a long one for eagle and another long one for birdie yesterday. But also missed 3 fairly short ones. Getting 3 shots at every putt...that is pretty significant.
I still think a good example of what a score might be is a best ball tournament. My son has been a caddie at Hazeltine for 8 or 9 years. He has caddie in groups with Rich Beem (won at Hazeltine), Ben Crenshaw and Davis Love (when they came out to Hazeltine to scout the course for the Ryder Cup). When they have best ball tournaments at Hazeltine there are tons of teams that come in at 15-20 under par. Same course, same greens.....shorter length. Spieth would not walk into Hazeltine today from the tips and shot 59. A more realistic score would be 65-66 depending on the pins.
On the flip side if you go to a course down the road without alot of danger...then his score could go into the 50's. A course where all of the the par 5's are reachable in 2 (realistic score would be 6 under on those holes.....would assume he hits at least a decent drive, then he has to make either a good to great iron shot or a long putt....those are not guaranteed) and 4 of the par 4's are reachable (should be 4 under at worse). The par 3's are 180 to 210 from the tips with just sand in the front (what is realistic 2 under?). Leaves 6 non driveable par 4's probably driver 7 iron (maybe 4 under par). That is 16 under or 56. To shoot in the 50's on any course you still need to hit allot of quality shots. That didnt take into account many bad shots. Yank a drive or iron OB, end up in the water on a shot. If the our played an event their....someone would go real low. One guy on one day....no guarantee he shots that low no matter how good he is.
Just to further my point....Jordan plays a 9 hole par 3 course.....just for example he hits all of his irons to 6 feet.....that is way better than average.....he shots 6 under.
If all of the distances were 150-175 yards....Jordan lead the tour....average distance is 22 feet from the pin.....he shots 2 under.
You still have to make shots no matter how easy the course.