The phrase 'Hand Down' means Easily, or unquestionably.
Example of use: "Rob is hands down the biggest threat for me in the competition."
The origin of the idiom “hands down” is found in horse racing history and dates back to the middle of the 19th century. When a horse was so far ahead of the rest that a win was assured, the jockey would loosen his grip on the reins and drop his hands as he and his horse approached the finish line.