tournament_contest_winner_captain_effect

tournament_contest_winner_captain_effect = {
	if = { # Original captain
		limit = {
			any_guest_subset = {
				name = team_$WINNER$_captain
				phase = tournament_phase_$CONTEST$
				is_alive = yes
			}
		}
		random_guest_subset = {
			name = team_$WINNER$_captain
			phase = tournament_phase_$CONTEST$
			save_scope_as = contest_winner
		}
	}
	else = { # New captain
		random_guest_subset = {
			name = winner
			phase = tournament_phase_$CONTEST$
			limit = { is_alive = yes }
			weight = {
				base = 1
				tournament_team_captain_modifier = yes
			}
			save_scope_as = contest_winner
		}
	}
	scope:activity = {
		set_variable = {
			name = melee_winner
			value = scope:contest_winner
		}
	}
	# Save losing captain
	if = {
		limit = {
			any_guest_subset = {
				name = team_$LOSER$_captain
				phase = tournament_phase_$CONTEST$
				is_alive = yes
			}
		}
		random_guest_subset = {
			name = team_$LOSER$_captain
			phase = tournament_phase_$CONTEST$
			save_scope_as = second_place
		}
	}
	else = {
		random_guest_subset = {
			name = second_place
			phase = tournament_phase_$CONTEST$
			limit = { is_alive = yes }
			weight = {
				base = 1
				tournament_team_captain_modifier = yes
			}
			save_scope_as = second_place
		}
	}
}

As written in game/common/scripted_effects/04_dlc_ep2_tournament_effects.txt.