defragmentation. Who is to be trusted here?

Question

Iron

Drives C, D, E
Win7 - claims to be defragmented by 4, 8 and 12%
Defraggler - by 16, 30 and 25%

Answer 1

Different algorithms, and Windows seems to judge by prefetch. I use Auslogics Disk Defrag with settings, everything seems to match with Windows

Answer 2

Each program has its own defragmentation algorithm, in turn, its own criteria for determining the degree of fragmentation