How to Count your Score:
Each player counts the total value of their unmatched cards. If the knockers count is lower, the knocker scores the difference between the two counts. If the knocker did not go gin, and the counts are equal, or the knockers count is greater than that of the opponent, the knocker has been undercut. In this case the knockers opponent scores the difference between the counts plus a 10 point bonus.
A player who goes gin scores a bonus 20 points, plus the opponents count in unmatched cards, if any. A player who goes gin can never be undercut. Even if the other player has no unmatched cards at all, the knocker gets the 20 point bonus; the other gambler scores nothing.
This card game continues with further deals until one players cumulative score reaches 100 points or more. The player then receives an additional bonus of 100 points. If the loser fails to score anything at all during the game, then the winner's bonus is 200 points rather than 100.
In addition, each player adds a further 20 points for each hand they won. This is called the line bonus or box bonus. These additional points cannot be counted as part of the 100 needed to win the game.
After the bonuses have been added, the player with the lower score pays the player with the higher score an amount proportional to the difference between their scores.