Auction bridge
The card game auction bridge was developed from straight bridge and was a predecessor to contract bridge. Around the same time five hundred was created by the United States Playing Card Company in 1904.
The main difference between auction bridge and contract bridge is that in auction bridge a game is scored whenever the required number of tricks (9 in No Trump, 10 in Hearts or Spades, 11 in Clubs or Diamonds) is scored. In contract bridge the number of points from tricks taken past the bid do not count towards making a game, but are scored separately as overtricks. Because of this, accurate bidding becomes much more important in contract bridge: partners have to use the bidding to tell each other what their suits and strengths are, so they can judge their chances of making a game.
Play
The bidding, play and laws of auction bridge were the same as contract bridge.
Scoring
A scoring table for Auction Bridge, from the Official Rules of Card Games, 1973 is as follows:
Odd-tricks: no trumps are worth 10; spades 9; hearts 8; diamonds 7; clubs 6.
Game was 30 points, and only odd-tricks counted towards game. The first side to win two games won the rubber and scored a 250 point bonus.
Each under-trick was worth 50 points to the opponents.
Small slam was worth 50 points; grand slam was worth 100 points.
Honours were scored as follows: 4 trump honours in one hand 80; 5 trump honours or 4 aces in no trumps in one hand 100. For an addition honour in partner's hand, or for 3 or more honours divided between both hands 10 each.
Contracts could be doubled and redoubled, which doubled or quadrupled the odd-trick and under-trick amounts. In addition there was a bonus of 50 points for making a doubled contract and for each over-trick, this was doubled if the contract was redoubled.