Calculate the proc frequency as normal. Based on that, you can figure out the expected average proc interval. We also now keep track of time since the last successful proc (this is different from the time since last chance to proc), capped at 1000 sec. Multiply the proc chance by MAX(1, 1+((TimeSinceLastSuccessfulProc/AverageProcInterval)-1.5)*3). For example, if a proc has an average proc interval of 45 sec, and it’s been 72 sec since your last successful proc, you’ll get a 1.3x multiplier to your proc chance. If you’ve been out of combat for a few min, and it’s been 5 min since your last successful proc, you’ll get a whopping 16.5x multiplier to your proc chance.