Solution: Board game variant used as a last-resort tiebreaker - NYT Crossword

I loved this pair of span entries dearly. At 52A, the [Colorful knit top with Scottish origins] is a FAIR ISLE SWEATER, which is a flat-knitted sweater that often has a patterned yoke made by skillful use of multiple strands of yarn. This style originated on the southernmost part of the Shetland Islands, which has fewer than 100 full-time human inhabitants (and quite a few sheep). 55A, [Board game variant used as a last-resort tiebreaker], is ARMAGEDDON CHESS. The rules give each opponent an advantage: One player gets more time to plan each move, but the other will win if the game is a draw, which makes it impossible to be locked in a stalemate.