What is the etymology of handicap?

The word "handicap" comes from the 16th century and originally meant "a disadvantage imposed on one side in a game or contest to level the chances between the competitors". It is derived from the phrase "hand in cap", which referred to a practice in horse racing where one rider would handicap another by carrying extra weight in their cap. This practice was meant to level the playing field between horses of different abilities. Over time, the term "handicap" came to refer to any kind of disadvantage or obstacle that makes something more difficult.