I have a hard time answering this question, because every time I go out, the Golfing Gods decide a different part of my game will be my nemesis. My bottom line for scoring is that I generally score in the low to mid 80's, and when all of the different parts of my game are working I will shoot in the 70's. When three or more are slightly off, I will score in the high 80's/low 90's. Personally, I break my game down to 1) driving; 2) fairway shots; 3) short game; 4) putting; and, 5) course management.
My failure to break 80 can be the result of one or more of these areas. Examples: 1) Earlier this year I shot 81 after hitting trees on 11 of 18 holes. Obviously, my driving was horrible, but my course management was excellent and was supported by my short game and putting. 2) Several years ago I played a round where I hit 15 of 18 greens in regulation and shot an 81 (9 over par). Obviously, that day my putting was my downfall. 3) Most recently I played two courses on vacation where I shot 84 and 82, and my downfall was course management where I did not recognize where the trouble areas on the course lurked. 4) Often, when I reexamine my round, had I hit a few more good chip/pitch shots closer to the hole, or made a putt or two, I would have broken 80. So, in summary, you can see that my bottom line in scoring can be affected by any of the five areas of my game.