About position eligibility in Fantasy Football
Position eligibility is determined by a player's past participation and info our data provider collects from NFL teams. Our data provider makes the final decision (there's no set criteria) on position eligibility including when a new position is added. If it's determined that a player's primary position has changed, then that player gains eligibility for the new position but won't lose their original designation.
Rule Clarification (Nov 19, 2021): The player will lose their original position eligibility if it is determined they have switched from one position type (offensive, defensive, or kicker) to another. This type of change is a rare occurrence and will be made only at Yahoo's discretion after their primary position has been changed by our data provider.