My understanding, from reading about other people's experiences is that it can take 3-6 months but its a ymmv kind if thing.
Rebucketing changes the weight of factos such as AAoA, Utilization, and number of cards reporting a balance. In my case when my oldest account reached 4 years my FICO plunged from 750s to 690 without any other changes. The reason, which became apparent over the following weeks, was the new scorecard (bucket) weighs the number of cards with zero balances very heavily and the earlier bucket didn't. Since all my cards had small, but non zero balances at the time my FICO dropped like a rock. This makes sense since when you first have credit you are likely to use all your cards and utilization counts more heavily then. I fully recovered simply by adding a new account and zeroing another account. In all cases my util was low.
Remember, the percentages that each publsihed factor has is a global average. Buckets each have their own weights which can deviate from the averages. So, if you are rebucketed just try different things to see what the FICO score is most sensitive to in the new bucket.
Very informative. I was trying to figure out why my January scores sank like the Titanic despite falling balances and increased limits when I remembered something about scorecards being discussed here. Now I feel a little less bummed out.
