I recently joined a project and it appears they matched me beside another y match of the same name. There appears to be 8 mismatches in the y-DNA markers but they are all in the fast changing markers. The slower changing markers are all identical. I'm not sure if they just put them beside each other because the names are similar or because they are discounting the fast changing markers. Any ideas?
I do not know which project you are referring to but it is very likely that both the name (associated to a given dna type) and the lower weight given to fast changing markers play a role. Regarding fast changing dna, it is known that these fluctuations are much faster and more frequent on short time scales than on long time scales. (they average out, or get 'expunged' over longer time scales, see this nice article by Quanta)