This article defines MDF (Made the cut but did not finish) and explains its significance.

If you see the designation MDF next to one of your golfers on your team page, it means that he Made the Cut, but Did not Finish the tournament.

The PGA TOUR enacted the MDF rule in 2008 in an effort to keep field sizes manageable.

Regular PGA TOUR events, which typically start with fields of 132-156 players, have long had a 36-hole cut with the top 70 players and ties advancing to the final two rounds.

But in 2008, in an effort to keep field sizes smaller, the PGA TOUR Policy Board enacted a new rule. The top 70 and ties still make the cut, but if the cut exceeds 78 players, only the number of golfers nearest to 70 continues in the tournament.

For example, in the 2008 Sony Open, there were 87 players at even par or better after 36 holes of play. Before the MDF rule, all of them would have both made the cut and continued play. But, because the number was greater than 78, some of the golfers were given the MDF designation. There were 69 players who were 1-under par or better. Since that was the nearest number of players to 70, only those 69 played the final two days. The other 18 players were given the MDF designation and did not finish the tournament.