i have read various articles that compare the 2 methods of running in and to test only one engine using each of the methods is hardly conclusive

however, most of the articles come to the same conclusion, so that does tend to hint that one way is better than the other - the hard throttle version as described similarly by Garage 19 and Chip.

one thing i don't really understand though, is how combustion pressure can act on only the inside of the ring to push it against the cylinder wall. surely pressure acts over the top and both inside and outside of the ring?