'AVERAGE PLAYER QUALITY' columns summarize the distribution of player skill in each field. These values are expressed in units of strokes better (+) or worse (-) per round than the average PGA Tour field. 'AVERAGE' is the average skill, 'TOP 25%' is the average skill of the top 25% of the field, and the remaining columns are defined analogously (according to the column header).

'DIFFICULTY TO WIN' columns are estimates of the probabilities that certain "player types" will beat the field. 'EURO' is the win probability for a golfer who has the average skill level of European tour fields (i.e. skill of -1); 'PGA' is the win probability for an average PGA Tour player (i.e. skill of 0); 'TOP 5' is the win probability for a Top 5 player in the world (i.e. skill of +2).