The Shapley value of a player is the difference between the average coalition payoff if the player is a member and the average coalition payoff if the player is not a member.
If N is the set of players, S is an arbitrary coalition of players that does not include player i, andv is the payoff function, then this formula computes the Shapley value of player i:
Instead of computing the sum over all 2N possible coalitions, the Aster Analytics Shapley Value feature computes an approximate Shapley value by sampling over coalitions whose observed payoff values are included in the user data.