What two come next in this sequence:
PN, BP, KT, RK, ??, ??
I think your on the right track Wild Guess but I would suggest "QN, KG" instead since it appears the peices are being sorted first by chessic value then alphabetical name (ie: PN (value = 1), BP (value =3), KT (value = 3), RK (value = 5), QN (value = 9), KG (value = priceless)