Using actual SSA numbers encounters various problems. However, using the estimated SSA from tools such as the Hole Forecaster (only available to designers who are members of the DGCD) or charts such as the “Estimated hole scoring averages for each player level based on length” can overcome most of these difficulties. Since these tools only give estimates there is a margin of error, but this is within tolerable limits of expected variation. Using estimated score averages the holes that give the most concern are those on the boundary between pars such as 3/4 or 4/5.
Using actual SSA is problematic for the following reasons:
1) Courses that have had many tournaments have multiple SSAs based on varying layouts. How can you come up with just one number for SSA? Do you take the most recent? or do you average all those with the same layout? You also have to know the layouts used and they are often not very well described.
2) What do you do about courses that don’t even have any SSA because they’ve never had a PDGA tournament?
3) There is nowhere online that hole by hole score averages are easily available.
4) And to make it even harder, what if you play a layout that is a mixture of the A&B basket positions? How could you find out the SSA for the specific layout you played? There would need to be an online database that has hole by hole SSAs for each layout. This doesn’t exist.
4.1 The problem of layouts that have several tees and several basket positions really complicates matters. For example, figuring out how to calculate the SSA of a round you play at Seneca or Calvert is nearly impossible. They both mix up the baskets so much, how could someone ever know which combination of baskets was played on the day that a particular SSA was calculated? And even if you had that data you would still have to know the SSA for every hole in every layout and then very tediously compare your particular round hole by hole. At Calvert there are almost 9 complete layouts! In the case of Seneca the standard layouts (e.g. Red-A) are only played in tournaments, and every other layout has a mixture of basket positions. So no casual round you ever play at Seneca will ever match the SSA that it recorded. You could only compare your score to SSA if you played a tournament round and many people don’t play PDGA tournaments. The only conceivable way to compare a casual round to a tournament SSA would be to get access to the hole SHS data for every layout. Then you would have to piece together your round for the A, B, or C data. That's nearly impossible.
5) Also, how do you know that the SSA listed even matches the current layout? What if they changed the course layout between the time that the SSA was posted and the time you played?
6) SSA is variable even with the effects of foliage and weather (esp. wind and rain). To use the PDGA SSA numbers you need to know if there was any unusual weather on that day in that location. Getting information like this is very difficult. You also need to factor in the season of the year. In warmer climates courses with heavy vegetation play harder in the summer than in the winter. In colder places such as Minnesota and Wisconsin the courses play harder in the winter because of cold, snow, and ice.