Good is somebody who delivered and allowed the company to overcome obstacles, without leaving a profound impact on its culture. Great is somebody who leads his company to achievements and performance and value that nobody was expecting it had. ↗
I would say a good leader brings results. A great leader writes a new story, it's different. Obviously a new story has to incorporate a lot of results. But a story is a chapter in the life of a company that people want to write and want to remember. ↗