My suggestion would be record all your GW games for a few days and use those for data initially. Or if you feel it happens more in Ranked PVP then do 10-15 or so of those and record them. And then use those videos as a starting point. Either post them here on the forums, or ask a guild mate who you trust to not be biased to look over them.
The other thing is to be strict with your criteria as to what is considered “lucky” and what isn’t, and make sure it’s applied equally across all your recorded games. Sirrian actually detailed some of the criteria they’ve used in tests in your other thread, and that would probably be a good starting point.