Just googled this: liked the last 5 words!!!
"Players generally cut holes in their socks in order to reduce pressure on the calf muscles, which are often restricted by the form-fitting, snug nature of the garment.
For players who have bulging leg muscles, socks can prove particularly restrictive, causing difficulties with effective bloodflow and circulation, as well as breathability.
Therefore, players will often move to cut up their socks, in order to remove the problem and help improve their game."