Four years ago, credit scoring had little to do with mortgage lending . When reviewing the credit worthiness of a borrower, an underwriter would make a subjective decision based on past payment history.

Then things changed.

Lenders studied the relationship between credit scores and mortgage delinquencies. There was a definite relationship. Almost half of those borrowers with FICO scores below 550 became ninety days delinquent at least once during their mortgage. On the other hand, only two out of every 10,000 borrowers with FICO scores above eight hundred became delinquent.

So lenders began to take a closer look at FICO scores and this is what they found out.   The chart below shows the likelihood of a ninety day delinquency for specific FICO scores.