Added performance tests to ruby and python, js is still lacking.

I also updated JS and CS translations now, so this suggestion is fully implemented, from my perspective. Marking this as resolved. Thank you.

I updated Ruby Example Tests, please try it and tell me if you find it okay like this.

That makes sense. I've added a case with custom k-factor algorithm to Python:

Test.describe('Testing custom K algorithm')
def k_algo(exp):
    return 800//len(exp)
Test.assert_equals(elo([1000, 1025, 1050, 1075, 1100, 1125, 1150, 1175, 1200, 1225,
                        1250, 1275, 1300, 1325, 1350, 1375, 1400, 1425, 1450, 1475,
                        1500, 1525, 1550, 1575, 1600, 1625, 1650, 1675, 1700, 1725], 1000, 0, k_algo), 1699)

But I'm no Rubist, so I would be thankful if somebody translates that into Ruby. Don't have much time at the moment, so I did not touch JS and CS yet as well, let's put it into todo-list.

What do you mean by that? I look at Ruby test suite and I can see several packs with custom K factor algos actually there. Please explain what you want.