Originally Posted by RogerSmith
I think I can explain this very easy - without using fancy charts, regression, or even a Pearson Correlation Coefficient: You are looking at unofficial results. Wait until the results are official, and then take another look at these events.
The key difference between the example 1977 gave and one where 'official' ratings might really fix the issue is the two-week gap between the two events. This isn't a combined Pro/Am event, where between unofficial and official rounds all pools that played the same course and layout will get combined (as long as the round results are fairly similar) (thus effectively averaging the SSA). This is a 4-round Pro event, and then two weeks later a 4-round Am event on the same course. The two event dates may not even be in the same rating cutoff (I didn't check).