When I had a CC that was reporting about $7K jump to $11.5K (out of $20K), I lost 3 points, but when I let a card that was reporting $0 jumped to $160 (out of $10.8K), I lost 10 points!
The number of CC reporting a balance is very important. Don't let more than half of your CC report a balance. Also, it reduces the score to let all repost $0.
