Why can different card groupings be counted separately in a cribbage hand?

In cribbage, the rules dictate that every possible different grouping of cards within a hand (including the starter card) must be counted separately to determine the total score. This method is a fundamental aspect of the game's scoring mechanics, as it rewards players for identifying all valid combinations—such as 15s, pairs, and runs—that can be formed from the five cards available to them.1

The only exception to this rule is that a sequence of four or five cards may only be counted once; it cannot be broken down into multiple, overlapping sequences of three to gain additional points. By requiring players to identify and calculate these distinct groupings, the game adds a layer of strategic depth to the "showing" phase, where players must carefully analyze their cards to ensure they do not overlook any potential points.1