The guards get blamed, then the players, then the wash. The sock is usually the answer, and it hides in plain sight.
Size and grip are different properties
A knit can keep its dimensions and lose its return.
So the sock still looks right, measures right, and no longer holds anything.
What kills recovery
Hot washes, tumble driers and fabric softener, in that order.
Twenty households washing twenty ways is the real test a squad sock faces.
What to specify instead
Elastane content, band depth and tension, and recovery after repeated washing.
Then a care label that actually asks for warm washes and no softener.
The quick diagnosis
Hold a new sock and a season-old one side by side and stretch both.
Same length, different return, is the whole story.