First attempt:Nerzhul wrote:What EBT needs is a good metric for the "interestingness" of a hit. It should be as simple as possible, transparent, fair, universal and comprehensible. A score by which all hits can be ranked and filtered and whose outcome roughly represents the order a normal, unbiased user would apply.
Hit ratio location 1 * Hit ratio location 2 * ... * Hit ratio location n / Instances of hits between n locations
Helmbrechts-Helmbrechts hit: 64,68 * 64,68 / 1433 = 2,92
Helsinki-Tampere hit: 43,36 * 37,72 / 1546 = 1,06
Berlin-Ljubljana hit: 241,93 * 87,56 / 9 = 2.353,71
Zaragoza-Bari hit: 2523,24 * 1926 / 1 = 4.859.760,24
Frankfurt-Groningen-Leuven hit: 204,58 * 106,89 * 103,85 / 1 = 2.270.945,71
Klagenfurt-Vienna-Vienna-Vienna hit: 101,63 * 103,96 * 103,96 * 103,96 / 1 = 114.188.071,44
Critcism: Ridiculously biased towards hits with places with poor hit ratios and towards multiple hits. Formula doesn't take distance into account, resulting in the Helsinki-Tampere hit being LESS interesting than a local Helmbrechts hit due to Finland having better hit ratios. However, a different pair of Finnish cities would probably have a better score (less hits between them), so the formula, while needing some work, doesn't appear to be completely broken. It might be a start to build on...