* neighbor's score is at least two points lower than the current cell's score,
* re-set it to 1 point higher than its lowest-scored neighbor. Repeat this
* whole process until all cells have settled on their final score. Ignore cells
* neighbor's score is at least two points lower than the current cell's score,
* re-set it to 1 point higher than its lowest-scored neighbor. Repeat this
* whole process until all cells have settled on their final score. Ignore cells