I analyzed the round ratings for the first three rounds of the 153 players who made the cut at the USDGC. Here are some nuggets obtained from that analysis.

Using the average difference between a player's rating and their average round ratings, the standard deviation of this difference is 16 rating points. That means 2/3 of the players shot within 16 rating points of their rating on average. Since a throw is about equal to 5.7 rating points on this course, about 70% shot within +/- 3 shots of their rating, despite all of the OB penalties. This standard deviation is almost exactly the same as the overall standard deviation we've calculated for all ratings we've processed for the pool of players who average around 1000 rating. So, even though Winthrop is longer with more OB than most courses in the world, it statistically doesn't seem to skew ratings information (now that we've made adjustments).

No player among these top 153 had a round more than 75 points higher or lower than their rating. Considering the OB challenges on this course, it seems surprising that a few players don't have a few rounds more than 100 points below their rating. I did see at least one in the group who missed the cut.

The average rating is 981 of the 51 players whose average round rating was at least 5 points above their rating in the first three rounds. The average rating is 994 for the middle group of 49 players whose average round rating fell between +/- 5 points of their rating. The average rating is 1001 for the 53 who have averaged more than 5 points below their rating.

Of all 19 international players in the final 153, so far 8 (42%) have played better than their rating. Among the 47 U.S. players with ratings of 1000+, 16 (34%) have played better than their rating. Among the 8 international players with ratings of 1000+, only 1 has played better than his rating.

So, it's possible that there has been some inflation in international ratings among the top players. Although I think it's more likely an effect that depresses top player ratings in the U.S. Typically, Europeans, especially Scandinavians, have higher average ratings among their Open divisions than in the U.S. which has many more B, C & D tier events where top pros will play perhaps several local events with lower rated players. We've determined that the higher average rating pools earn slightly higher SSAs. Once we adjust for this effect within the next rating update, I think we'll find that top U.S. players will be able to achieve and maintain their high ratings if they play well.

None of these effects is particularly strong but visible enough that we'd like to address them so our ratings playing field is as level as we can make it across the world. Regardless, when everyone comes together, throw the ratings out the window because you still have to play well to earn the titles.

So, it's possible that there has been some inflation in international ratings among the top players. Although I think it's more likely an effect that depresses top player ratings in the U.S. Typically, Europeans, especially Scandinavians, have higher average ratings among their Open divisions than in the U.S. which has many more B, C & D tier events where top pros will play perhaps several local events with lower rated players. We've determined that the higher average rating pools earn slightly higher SSAs. Once we adjust for this effect within the next rating update, I think we'll find that top U.S. players will be able to achieve and maintain their high ratings if they play well.

None of these effects is particularly strong but visible enough that we'd like to address them so our ratings playing field is as level as we can make it across the world. Regardless, when everyone comes together, throw the ratings out the window because you still have to play well to earn the titles.



I totally agree. I've come across a few Scandanavian disc golfers at Pro Worlds and they were very good golfers, and could throw a country mile, but I've always thought the number of 1000+ and 990+ golfers there seemed a little high. Take a look at the players entered into the European Disc Golf Championships; (http://www.pdga.com/tournament/tournament_results.php?TournID=4668#Open) look at how many golfers rated 990 or better there are.

Could this phenomenon be attributed to the fact that they they don't split out golfers into an Advanced division?

Chuck,

I had a thought about these ratings, especially since so many were rated way above 1025 round after round.

It would be a litmus test and not purely a rag on the ratings system, but it would be interesting to see how the round ratings faired out if you took all the players in the tournament, dropped their rating by 100 pts and see how the round ratings would differ.

Because doesn't it work that if a 1000 rated player was the top propegator and shoots a 56, then that is a 1000 rated round, but if a 950 rated player was the top propegator and shoots a 56 on the same course/same conditions, then that 56 would be a 950 rated round?

I know you work tirelessly on making the ratings system as objective as possible, but with any statistical analysis there are always subjective inputs.

I am purely curious what the new round ratings would be if the individual player ratings were dropped by 100pts. (This would reflect an Am tournament).

It wouldn't mean anything because either those players wouldn't shoot those scores. Or if they did, the course SSA would be quite different so you don't learn anything. The only way to compare would be to calculate the SSA using scores from the top half of the field and compare them to the SSA calculated from the bottom half of the field. We've already done that with other events that have a wider range of ratings than USDGC to determine what adjustment we need to make in the formula next time.

did you check out Markus Kallstrom's Last round? 56 unreal!

did you check out Markus Kallstrom's Last round? 56 unreal!



Just think, Climo shot the same score in 2004 when the course played 2-3 strokes HARDER. Now thats unreal!!