The mystery of how credit scores are calculated will never be solved. Who cares?
After being told I am a bad boy for "not using" my credit cards enough, and having my score dinged by 18 points, I get a note from Experian telling me my credit score has been increased by 32 points (29 points and then three more as shown above) as "inactive accounts have become active." In other words, I let a small balance carry over past the closing date, and the computers now think I am charging $52.50 a month on a card, when in fact I am charging far more.
But what is interesting is that I am now five magical points away from a "perfect" credit score, at least on Experian. This is becoming like a game. Could I make it to the "perfect" score? Well, probably not, unless I had a time machine. I would have to go back about 20 years and decide not to close my Sears credit card account. Or I would have to decide not to pay off my mortgage.
You see how the system works - debtors are favored, those with real wealth are not trusted.