[MLB-WIRELESS] MW Scoring system Overview

[Tom Fifield]

We've had a few requests for more information about the Melbourne 
Wireless node scoring system, so here it is . . .

You may have noticed that we've recently transitioned into a new way of 
providing scores for nodes - the top nodes, for example, instead of 
getting scores of 15, now get scores of 40. This new formula is far more 
accurate.

A bit of background on why the scoring system was implemented. Basically 
the leaderboards are designed to promote competition between members of 
the network, which subsequently fuels its growth as new interfaces, 
longer links and more services are added in an attempt to raise the 
score, gain the next position and so on.

Now, onto how we make the scores.

For the technically minded, the below is the php function that ends up 
making your scores;

function fudgeScore($value, $ideal) {
	return $ideal * (1 - 1/($value+1));
}

The English explaination is much simpler; we have a list of ideal values 
(below) for Interfaces, Number of Links and their total distance, as 
well as the number of services a node has, that are 'fudged' using a 
mathemagical formula to spit out a score.


Ideal Values
------------
Interfaces	3
Links		8
Distance	30
Services	5


The maximum score you can get for each separate item is just less than 
the ideal value. That is, if you had an infinite amount of interfaces, 
you would get 3 for that score component. That makes the maximum 
possible score just under 46.

However, if you're not a melb_ap or a bigjohn, that matters little :)

I think it's best shown on a graph, try : 
http://www.melbournewireless.org.au/files/Images/MW_SCORE.gif

That's a graph of distance vs score, which uses the ideal value of 30. 
See how one starts off accumulating a lot of points in the initial few 
kilometers, then levels off toward the end? It's the same pattern for 
all other score elements. As you get a better and better node, this 
means it becomes harder to get a higher score.

Once we have read in your nodes score for all of the elements, we simply 
add them together and shove them in the database. Whala, youre node has 
a score.

Similarly, the user/area scores are a cumulation of their respective scores.


Hopefully that was enlightening,

--Tom

*NB: Lazy coders have not properly implemented the new scoring system to 
several site functions. If you update your node and the score is wrong, 
come back in the morning and it will magically be fine.

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