I have recently upgraded BOINC. After seeing the major differences between requested credit and final credit I am left wondering something...

Between the various versions of BOINC there are various forms of computing credit. What is the significance of someone running a task and requesting credit based on "newCredit" vs. someone running a task and requesting credit based on one of the "oldCredits"?

I know many projects have gotten away from the default BOINC credit altogether. Many of the smaller projects, however, still use the "smallest of multiple runs" method to compute final credit.