First off, avoid 'Magic numbers' at all times in your program! It is extremely rare for a single use of a fudge factor in any program. Honestly, these adjustment numbers will, not might, WILL pop-up elsewhere as the program grows.
The only instances where such a number is used, that I can think of, would be in a mathematical equation (which really should be in its own routine anyways) or as a throw-away value only needed for debugging, e.g. the actual value does not matter just as long it is the same for each debugging session.
If a number is needed, consider making it a user defined value instead of a named constant. Many times the user will have a better idea as to the preffered value than the developer. (And many times the user will be a gormless git that will make a complete hash of things. But that is another rant.)
Case in point is the colour of the playing pieces. Now Black and White are considered traditional. But earlier, before mono-chrome displays, red was often used as the second colour in a number of games, i.e. Black and Red for backgammon and less commonly White and Red for chess. And what about adding an additional player? That third colour should be used?