the only thing I can suggest here (as this a running theme of you feeling victimised now Shanks)....
...is to record the result of every coinflip, every 60/40, every 70/30 and every 80/20 (on excel for ease).
Do this for ones involving you and for ones involving others seperate (you just may be doom switched!!) Take care to also record the times you get your money in bad and suck out (my speciality)
after recording about 200 of each you should be reasonably close to the above percentages (allow about a 5% swing ??)