Rule 31 Seniority in the Supreme Court

When Supreme Court judges need to rank themselves by seniority, they go by how long each judge has served without a break. The judge who has been on the court the longest is considered the most senior.

If two or more judges started on the same day, they cannot use length of service to decide who is more senior. In that case, they can either agree among themselves on the order, or they can draw lots, which is basically a random method similar to drawing straws or flipping a coin.