What is the best hand in cribbage and how does it contribute to winning the game?

The best hand in cribbage is a perfect 29 hand, which consists of a Jack of the same suit as the starter card and the other three cards that make a 15-15-15-4 combination. This hand contributes to winning the game by earning the maximum number of points possible in a single hand, which can give a significant advantage over the opponent and help secure victory.