Just in case the process of Enhancing Weapons has made anyone else wondering what pattern to use, even after reading all 9 pages of this thread.
I believe (after my own experience and 99% of this boards experience) that there is no Pattern. It is all Chance, it is Random and you are gambling with your weapon when trying to enhance it. If you don't use Cash Shop Stones IE; Blues Miles and Red Eyes when enhancing you will most likely break your weapon.
If someone tells you they get +9 all the time without using Cash Shop Stones they are Lying to you.
Definitions in case there is still confusion.
chance Pronunciation[chans, chahns]
1. the absence of any cause of events that can be predicted, understood, or controlled: often personified or treated as a positive agency: Chance governs all.
2. luck or fortune: a game of chance.
3. a possibility or probability of anything happening: a fifty-percent (less if you enhance weapons when playing Fiesta) chance of success.
4. an opportune or favorable time; opportunity: Now is your chance.
5. Baseball. an opportunity to field the ball and make a put-out or assist.
6. a risk or hazard: Take a chance.
ran·dom Pronunciation [ran-duhm]
–adjective 1. proceeding, made, or occurring without definite aim, reason, or pattern: the random selection of numbers.
2. Statistics. of or characterizing a process of selection in which each item of a set has an equal probability of being chosen.
gam·ble Pronunciation[gam-buhl] Pronunciation Key Pronunciation verb, -bled, -bling, noun
–verb (used without object)
1. to play at any game of chance for money or other stakes.
2. to stake or risk money, or anything of value, on the outcome of something involving chance: to gamble on a toss of the dice.
–verb (used with object)
3. to lose or squander by betting (usually fol. by away): He gambled all his hard-earned money away in one night.
4. to wager or risk (money or something else of value): to gamble one's freedom.
5. to take a chance on; venture; risk: I'm gambling that our new store will be a success.