Ouch. I thought I was having a bad day going through 121 craftsman's cunning tier V for a 5th meld on an offhand. I've come to terms with anything not being 100% might as well be 0%. On the flip side, sometimes RNGesus does take pity on you. On two other offhands, I got the same meld to go on first try, so between the 3 of them, the percentage was closer to the stated 5%.