Forge of Potential predictor
Whether your next refine goes up or breaks, for 244 items
Tries so far means attempts at this exact item and quality on patch 1.0.20 or later, on any copy. Rolls before 1.0.20 were not seeded and do not count.
Since patch 1.0.20 the Forge of Potential doesn't roll fresh dice. Each attempt is seeded from your character's name, the item and the quality you are refining to. The game draws one number, and the item goes up if it is 65% or under and breaks otherwise. Then it saves a new seed with your character for the next attempt at that item and quality. The whole run is fixed in advance, and this page works it out with the same random number generator the game uses.
That's also why quitting and reloading no longer helps: the saved seed comes back with the character and the same roll lands again. What you can choose is which copy takes a roll. If the next try at quality 5 is a break, spend it on a spare at quality 4 and save the success that follows for the item you care about. Every try costs an idol either way, and a break hands back 35% of the materials, rounded up.
Two things decide where you are in the run. The name has to match the game exactly, capitals included, because the seed hashes it letter by letter. And only attempts made on 1.0.20 or later count, since older ones never touched the saved seed. Each item and quality has its own run, so refining an Iron Sword to 5 does nothing to its run at 6, or to an Iron Sword on another character. The odds, idols and costs are on the Forge of Potential guide.