One of my Kws dropped to page 8 from page 2. According to ahfres, the most used anchor phrase accounts for 16%, I think it's OK, but the most used anchor term accounts for 57%, I guess this is why my ranking dropped. For example, my Kws anchor phrase "best shoes" accounts for 16% , but anchor term "shoes" accounts for 50%. I just realize this problem. That was my speculation, I will lower the percentage and see what will happen.