When a player bingos, the nabors are determined by the ball number that bingo was called on. 1-18 - 1st nabor up and 1st nabor down; 19-36 - 2nd nabor up and 2nd nabor down; 37-54 - 3rd nabor up and 3rd nabor down; 47-72 - 4th nabor up and 4th nabor down; 73-90 - 5th nabor up and 5th nabor down.