Beanbags
The beanbags are literally filled with dry beans. These can be purchased from any grocery store or supermarket. There is really no advantage to any one type of bean; however, you want each beanbag to weigh several ounces so that it can travel a decent distance in the air after it is thrown. While you may construct any size beanbag you like, 6-inch-by-6-inch squares of material will give you a decent-size bag. They can be fashioned from felt, cotton or any other synthetic material that will hold up to being thrown multiple times. One of the keys to making a good beanbag for this game is to ensure that the stitching is tight all the way around the bag. It is optimal to use a sewing machine that will provide tight, close stitches.
Clapboard
The other important element needed is the clapboard associated with the game. To form the clapboard take two sheets of cheap plywood and bracket them together using medium gauge brackets. The plywood does not need to be exceedingly thick. A half-inch to a full inch will do. The brackets are secured on one end of each piece of clapboard so that it stands erect and forms an inverse "V" shape. The clapboard should now stand on its own. Next, holes should be cut out of the clapboard for game play.
Cutting Holes
At this stage you want to determine how complicated you want the beanbag baseball game as you must cut out corresponding holes. For instance, while you need to cut holes for offensive plays such as a hit, double, triple and home run (so that a team can score) you can also add holes allowing for actions such as steal, squeeze play, balk, wild pitch or any other specialty occurrence. The more difficult the play, the smaller should be the hole. This means the "home run" hole should be much smaller than the "single" hole.
Paint the Beanbag Baseball Board
Now that the holes are cut, each hole must be painted to alert the player of the corresponding result from their beanbag throw. Paint the entire plywood board a base color, then allow it to dry. After that, paint words beneath each hole respectively until they are all matched. Feel free to create other designs on the clapboard such as a baseball diamond, or scorecard that will help you highlight where you are in the game. You can write in the score grid boxes with a piece of chalk, indicating any score achieved during each game.
Forming the Rules
Since you are constructing the beanbag baseball game, you have pretty wide leeway deciding on the specific rules. However, you want to make sure the basic tenets of baseball, such as hits and three-out innings, are retained. One good way to go is that every player who is tossing the beanbag is on offense, or at bat. If the "batter" gets the beanbag through a hole, then that offensive action takes place. Any missed throw with a beanbag would be recorded as an out. Also, runners can only move as far as they are forced. So unlike real baseball where a runner on second can score on a single, in beanbag baseball, a runner would only advance one base to third. As in real baseball there are three outs to an inning and nine innings to a game. The person who scores the most runs wins.