Document to self (and anyone interested):
cash_hand_player_statistics.holecard_1%13=LEAST(cash_hand_summary.card_1%13,cash_hand_summary.card_2%13,cash_hand_summary.card_3%13,cash_hand_summary.card_4%13,cash_hand_summary.card_5%13)
OR
cash_hand_player_statistics.holecard_2%13=LEAST(cash_hand_summary.card_1%13,cash_hand_summary.card_2%13,cash_hand_summary.card_3%13,cash_hand_summary.card_4%13,cash_hand_summary.card_5%13)
plus the quick filters for one pair.
Somehow I get an offset of a couple of hands when adding that to player report, compared to running the generated query in pgadmin, also player report gives one less hand that hand report... but close enough for cigar, I guess.