In golf scoring on the PGA Tour, the acronym MDF stands for "made cut, didn't finish," and has been somewhat controversial since it was first used on the scoreboard in January 2008. The term does not relate to a player who withdraws during the third or fourth round because of injury or other reasons.
Traditional professional golf tournaments consist of four rounds. After two rounds of play, the playing field is reduced dramatically. Usually, the top 70 players, including ties, make the cut and go on to play the third and fourth rounds. The players who finish outside the top 70 do not make the cut and go home without playing over the weekend.
Because the top 70 finishers including ties traditionally qualified for the weekend, there could easily be considerably more than 70 players in the third and fourth rounds. This excess number could lead to tee time scheduling problems, as tournament organizers would be forced to accommodate more golfers than expected.
The MDF rule specifies that if more than 78 players qualify for the final two rounds, the cut score will be lowered to the next available score. These golfers receive an MDF note beside their name on the tournament's official scoring. They each earn a portion of the tournament's purse but do not continue play. The rule has been met with some criticism from the media and professionals, who have argued that a player who makes the cut should be able to continue.
The PGA Tour developed this rule after analyzing data leading up to 2008. It said that in the previous 12 years' worth of tournaments, 136 events had 78 golfers or more make the cut, despite the recommended cutoff of 70. The PGA Tour argued that anyone who qualified despite being so close to missing the cut could not be a serious threat to win the tournament, making it easy to remove these players from competition.