Create a new score metric

[chrisnienart]

Currently top scores are indicated by lowest completion time, but do not account for game difficulty. A new single value metric should be recorded that combines time elapsed, size of the board, percentage of mines. The score should be defined in a way so that a higher value indicates better performance.

Constraints

• score should decrease with elapsed time
• score should increase with board size
• score should increase with mine percentage

[chrisnienart]

Created a metric called performance for won games. Still need to test whether this metric properly balances difficulty and completion time. There is currently no tracking or assessment for games lost.

[chrisnienart]

Performance should scale at less than a linear rate with board size. Consider using log(boardSize) instead.

[chrisnienart]

Possible solution for tracking lost games: scale performance by completed percentage metric. This metric would be a function of cells revealed, board size, number of mines, etc.

[chrisnienart]

Completed percentage added in Commit b25a882

[chrisnienart]

Used completed percentage squared adffa13. Difficulty for increasing mine percentage still understated, but good enough for now.