Note that a "median" is a special case of a 50% percentile. If you desire to apply a more stringent criteria you can use the 75th or even 90th percentile.

Perhaps if a statistician (i.e. not me) could be found to offer her services, she could become a resource for helping selecting the most appropriate statistical algorithms on request (and implemented Integer math as per Gavin, from memory), considering the consequences of learning post-fork that a "bad statistical model" was chosen.

e.g. an exponentially weighted moving average is usually much less volatile and harder to manipulate than a simple moving average, but still can "respond" to short term drivers. 

Regards,

Gary