Scottie pretty much always plays this way.
His distance control is impeccable and he almost never gets himself into a tough spot because he chooses "safer" targets. And yeah he hits a lot of "darts" - but he also hits an incredible number of boring shots 25 ft pin high right of a tucked left pin.
And he shot 68-64-67-68 for the week so it wasn't like round 4 was some tame scoring round - that final round 68 also had a double.
You can go to the Open Championship website and they have all the rounds charted out. He birdied the 1st hole 2 out of 4 days. Let's look at them real quick.
Round 1: Tee shot went to "native area" with a back pin; his approach was 60 feet short into the front of the green, 2 putt.
Round 2: Fairway, 169 to a back left pin - he hit it 7 feet right and made birdie.
Round 3: Semi rough off the tee with a tight front left pin: he hit it 34 feet right pin high, 2 putt.
Round 4: Semi rough to a dead middle pin - only 143 yards in. He hit it to 18 inches.
That pretty much says it all. First day he didn't get too aggressive and just took his medicine, second day he utilized his amazing distance control from the fairway but still kept it on the "fat" side. Third round he again took his medicine on the "fat" side, 4th round with a middle pin he just went right at it, he probably had a good lie in the semi-rough.
He's the best golfer in the world because he has amazing distance control AND he almost always makes the "correct" play. Tiger did the same damn thing and just wore everyone out.