A transaction in fantasy football is any action that involves acquiring or getting rid of players. Making timely and strategic transactions is a crucial element of fantasy football, often representing the difference between winning and losing a league.
One common type of transaction in fantasy football is trading. Trades are generally conducted between two teams and involve an exchange of players. Fantasy owners utilize trades to improve their teams, often by acquiring players that will add more production to a position of need. For example, if Joe has 4 solid receivers and below-average running backs, he may look to trade a receiver to Bob in exchange for a better running back.
Another type of transaction is adding and dropping players. Adds/drops involve players that are free agents, meaning they are not currently on a team's roster. Every now and then a fantasy owner will stumble upon a free agent that could greatly increase their team's weekly point totals. Due to a maximum roster size limit of 16 players, a player currently on the roster generally must be released into free agency in order to add the desired player to the roster.
Recently dropped players are often placed on the waiver wire. The waiver wire is designed to give each team a fair chance at newly tabbed free agent, with suitors placing a 'claim' for the player. A priority order is used to determine which of the teams that have submitted a claim will ultimately receive the player. Early in the season, the priority order is essentially a reversed draft order, with teams that selected later in the draft having the first crack a player. As the season progresses, the priority order is based on each team's total number of transactions. Teams that have rarely added players are assigned the highest right to a recently dropped player, while teams that tend to add/drop players on a weekly basis have a much lower chance of a successful waiver claim.
Placing an injured player on injured reserve (IR) also qualifies as a transaction. When a player sustains an injury and is placed on a real-life inactive list while recouping from the injury, fantasy owners have the opportunity to place that player on injured reserve. This temporarily opens up another spot on the roster until the player is deemed healthy and ready to play again, allowing owners to add a free agent to make up for the lost point output.
All league transactions throughout the course of the fantasy football season can generally be found on the league's transaction page. The page lists every trade and add/drop that has occured, allowing fantasy owners to keep tabs on the whereabouts of players they covet.