No need to be a programmer. Definitely some math, though.
(1-exp(-average(scores))) * 100... is just a mathematical expression.
scores is the value of the "scores" variable, which is actually the output of the Tournament Score formula (also in the Stats Profile). The Tournament Score formula is computed for each tournament (for each player), so
scores holds a set of values. For example, for a tournament with 25 people, if I busted out 3rd then my score would be 2.16 (from the Tournament Scores formula
log((n + 1) / r)). If I bust out 1st in a 50 player tournament, my score would be 3.93. So this variable might hold a set of values like (2.16, 3.93, .89, 1.10).
average() is a function that returns the average of the values you provide to it. For example,
average(1,2,3) would return 2.
average(10, 30, 80) would return 40. So
average(scores) returns the average of the player's scores.
-average(scores) just means the negative of the average score.
-average(scores) is the same as
average(scores) * -1exp() is a function that raises E (Euler's constant) to the power of the number provided. You'll have to look that one up. For this formula, it would be E raised to the power of the negative of the average of the player's scores.
Once you get to this point,
exp(-average(scores)), the result is going to be between 0 and 1, with the result actually being closer to 0 the better your average score. So,
1 - exp(-average(scores)), or subtracting this value from 1, basically inverts it such that the better your average score, the closer to 1 you get. Finally, multiplying by 100 changes the scale from 0 to 1, to 0 to 100. This is just an easier scale for most people to comprehend.
Also, do you know of a better tie breaker?
This is really personal preference I guess. The nature of the formula should keep ties to a minimum. When one does occur, you could say, for example, the player with the highest single score, or the player who played more tournaments (or fewer), etc.