For amateurs and casual backyard play, a typical 21 point scoring system is used that is similar to horseshoes. Match play, (best of three), is also recommended.
NOTE: There are variations to the scoring system depending on who you are playing with and where you are playing. To avoid an uproar, he or she who owns the board set should make the rules for those boards and the scoring and tossing rules should be agreed upon BEFORE you start play. Some will play the first that score 21 points or over wins while others will play that you must hit 21 exactly. If you go over you must go back to previous score and try again.
After determining who goes first by either coin toss or luck of draw, opposing players will throw one bag at a time until all four bags have been tossed by each player. A bag that lands on the board is worth one (1) point, a bag that goes through or is bumped down completely through the hole in the board is worth three (3) points. Most novice players will use this cancellation format where opposing players' points cancel one another out. Only those points that do not cancel out apply to the total overall score.
If Team Las Vegas throws two cornhole bags that land on the board, one misses and one goes through the hole, they will have scored five points. If Team New York threw one in the hole, one on the board and two that missed the board completely, they will have canceled out all but one one point bag from Team Las Vegas. Final total of that frame is Team Las Vegas plus one point. The difference is 1 (5-4=1). Team Las Vegas scores 1 points in that frame.
This game is all about having fun in the backyard but I've seen some great competitive cornhole tournaments where it's all about winning!