Rules Analysis
Every player is entitled to occupy any position on the field not occupied by any opposing player, provided that they do not initiate contact in taking such a position.
If a player does initiate contact in taking such a position, this is a Blocking foul (17.8). All players have a responsibility to avoid initiating contact, even if that means that they must pull out of making a play on the disc.
However when the disc is in the air a player may not move in a manner solely to prevent an opponent from taking an unoccupied path to the disc.
What:
Player A, who is making a play on the disc, is allowed to slow down and to impede a opponent's movement to make a play on the disc. However Player A must not move in a way that the opponent could not reasonably avoid them -- this is a Blocking foul (17.8). Some incidental contact may occur in these circumstances but incidental contact is not a foul.
Extra:
If Player A is not making a play at the disc, but is instead allowing a teammate to make a play at the disc, Player A may not move to impede an opponent. However if Player A is stationary, or does not intend to impede, this is not a violation, even if their actions do in fact impede an opponent.
Note:
The key word in this rule is 'solely'. The intent of the player's movement can be partly motivated to prevent an opponent from taking an unoccupied path to the disc, so long as it is part of a general effort to make a play on the disc.
However when the disc is in the air a player may not move in a manner solely to prevent an opponent from taking an unoccupied path to make a play on the disc.
What:
Player A, who is making a play on the disc, is allowed to slow down and to impede an opponent’s movement to make a play on the disc. However Player A must not move in a way that the opponent could not reasonably avoid them – this is a Blocking foul (17.4).Some minor contact may occur in these circumstances but minor contact is not a foul.
Extra:
If Player A is not making a play at the disc, but is instead allowing a teammate to make a play at the disc, Player A may not move to impede an opponent. However if Player A is stationary, or does not intend to impede, this is not a violation, even if their actions do in fact impede an opponent.
Note:
The key word in this rule is ‘solely’. The intent of the player’s movement can be partly motivated to prevent an opponent from taking an unoccupied path to the disc, so long as it is part of a general effort to make a play on the disc. If a trailing player runs into a player in front of them, it is nearly always a foul on the trailing player.After a turnover, and/or whenever a thrower is not at the pivot location, the defence must allow an unobstructed path by the offence to the disc and/or to the pivot location