They used to be assigned according to batting order, but nowadays players can be assigned a number upon their own request or by luck of the draw
they take control of the team and put their players in the batting order and also make decisions about where the players are going to play on the field
Originally they were given numbers to correspond with the batting order.
A batting lineup or batting order in baseball consists of nine players. The order of the batting order is determined by the manager of each team and can change during the game if the manager replaces players. In Major League Baseball (MLB) the American League (AL) employs a Designated Hitter (DH) rule in which another player (not among the nine field players) can bat in the place of one of the fielders, usually in place of the pitcher. The National League (NL) does not employ this rule.
they order them
A batting order is a sequence in which, in a game such as cricket or baseball, a side's batsmen go in to bat.
By order of the Commissioner of Baseball, number 42, Jackie Robinson's number with the Dodgers, has been retired from all Major League teams, although players who wore "42" prior to the Commissioner's order have the option of continuing to wear that number.
When the New York Yankees started putting numbers on their uniforms, they used the numbers 1-8 for the players that were starters. The number of the player corresponded to the position in the batting order that the player hit. Lou Gehrig hit fourth in the batting order, so he was given #4. Babe Ruth hit third in the batting order, so he was given #3.
The starting lineup in baseball is either nine or ten players, depending on the rules of the governing body. Some bodies allow a designated hitter to replace the pitcher in the batting order, but not when the team is fielding.
Baseball is a team game with nine players each on a side in which players attempt to run a complete circuit around four bases in order to score runs.
formula 1 drivers, baseball players, basketball players, and soccer players in no particular order but i know that soccer players get the most incentives in contracts of any sport