I have identified five places where I have problems with your approach.
Rather than repeat all you wrote, I'll just add a title in reference to what you wrote.
[living in an undirdie-able world]
(Had to modify that a bit to fit the Madonna song running through my head. Oops, sorry, now you caught the ear-worm, too.)
You're saying we should not call unbirdie-able holes unbirdie-able, because we don't like unbirdie-able holes?
Take a hole where no player gets a 2, and 90% of the players get a 3. On that hole it is impossible to gain a throw on the field. It should be called a par 3, because if you get a 3, you haven't gained a throw. Calling it a par 4 doesn't change the fact that a 3 won't let you gain on the field.
Whatever method we use to set par, it won't change the holes where it is impossible to gain a throw on the field. Unless….
We use a method where unbirdie-able holes are properly labeled so that course designers and TDs decide to make them easier (or enough harder to justify a higher par) rather than just slapping too high of a par on them to placate players.
You made me wonder how many holes actually are unbirdie-able. I have data on 237 holes that had enough 1000- and higher-rated players to compute gold par from the scoring distribution. It turns out that 37 of these holes would be unbirdie-able using my favorite method of setting par. Of these, 19 would be par 2s, 16 would be par 3s, 1 par 4 and 1 par 5.
[Identical hole being Par Three on a particular course and Par Four on another course.]
I've never seen an identical hole on two courses. How often does that happen? If it does, how often would those holes both be on the bubble par-wise? If they were, how often would they both be most nearly on the bubble of all holes on the courses? If they were, how often would those two courses both need any adjustment? If they did, how often would they need a different adjustment?
If the situation ever arises and it bothers you, then just make those two holes have the same par. Having a total par within 1 of ideal is quite acceptable. There is enough wiggle room that no single hole's par would be dictated by any goal for total par.
[what it really means is that par is the score WE expect the TYPICAL expert to get.]
The definition doesn't say which particular expert, so we're free to ask one with typical skills and realistic expectations.
[the USGA's definition of par]
Completely irrelevant to disc golf. This is a different game, with different rules, a different strategy, and different expectations. Our definition could have easily said "two putts" (because putt is defined in the rules) but it doesn't. I assume there is a good reason for that.
The PDGA definition of par, and the methods I've laid out, also get you par with errorless play and birdie with exceptional play. Two putts is often one-error play. One putt is not often "exceptional" putting, even at my skill level.
[When the course is designed for 950-rated players, and a par round is rated 950, does that tell you that par is about where it's supposed to be, or that less important than other measures?]
That tells me Blue par is about where it's supposed to be (probably about 2 too high, but close enough).
What bothers me is that it is not appropriate to use Blue par for the Open players. Just like it would not be appropriate to use Red par for the Advanced field.
[Is -3 in 2013, -5 in 2014, and -2 in 2015 (for two rounds). Consistent enough for par?]
Yes, I think so. Par works well enough within a range of +/-2 per 18 holes.
[Ratings and Par]
Ratings will always be a better indication of player performance than the score relative to par. That doesn't mean we shouldn't make par as useful as possible. Par has different uses and is useful in different contexts than ratings.
I don't think the ratings system can get to the point where you would be able to look at your scorecard and see how much your rating will go down if you get a 4 on this hole. But accurate par can give you some idea.
I do advocate using round rating data and players with known ratings to help guide par, when available. I include the method of using "contending players at big tournaments" because par is defined without mention of ratings, so there should be some method of setting it without ratings. (Besides, some people hate ratings and will not use any method of setting par that refers to ratings.)
But, if everyone set total Open par so that an even par round in ordinary conditions would be rated at least 1000, that would be great.
[Using the cash line to help determine par]
For the large tournaments, the mix of contending players that show up is surprisingly steady. If each of these tournaments used par based on the top 40% of players at their own tournament, then par at other tournaments would act very similar. Not as precise as using ratings information, of course, but good enough for a player to get a good idea of how well he or she is doing during the round.
Also, par should be above the cash line, in the "center mass" of all players who cash. This depends on all the contending players' scores, and therefore is even more stable than the cash line.
Smaller tournaments often don't have enough highly rated players to get enough data to set par based just on player scores. For these, an extrapolation from actual scores is the best we can do.
[Weather would cause par to change because scores would change.]
Using actual scores is a tool to use to help set par. It is not a replacement for the definition or the TD's judgement.
Part of the definition is "under ordinary weather conditions". So, if it's windy and rainy (and if that isn't ordinary weather conditions), you should not use those scores to set par.
However, even if you did, the best methods of setting par based on scores would be fairly insensitive to unusual weather, because par is not average. Average scores will go up because more players will get higher scores, but many players will still get the low scores.
Often, there will be enough players who still get the low scores, so that calculated par would come out no different on most, if not all, holes.
Also, it is unlikely that bad weather would persist all through every round at a tournament. So, these methods stand up well, even if you don't take the proper step of excluding rounds with unusual weather.
[OB should not change par.]
Yes, in general, more OB should not change par.
(A lot of people don't agree with this, because they think par is average. Which it is not. So, anyone who has heard me repeat "par is not average" every chance I get may find the following to be unexpected.)
There are ways where OB does legitimately change par, because errorless play doesn't mean best possible outcome, and is tempered by the requirement that it be common enough to be expected.
1. A strange example is where going OB is not an error. Take a short hole with the target placed on a 10 foot deep strip of in-bounds in the other side of a lake. The smart play would be to run at the basket and accept the usual drop-in circle 3 from the edge of the OB behind the basket. In that case, going OB is not an error, but a strategic use of the rule.
A similar situation could occur with an extremely generous forward DZ.
2. OB can change how players play the hole; the errorless tactic may be different because of the OB. Perhaps the ideal landing zone is now 75 feet farther away from the target because players adjust their throw to reduce the chance of very punitive OB. Or, perhaps players are driving with putters. In fact, if OB does NOT change how the player approaches the hole, it is kind of a weak use of OB.
3. The presence of OB can increase the scores by enough that expert players no longer expect a certain score. Example: If 50% of the 100-rated players are managing to make a 3 on a hole, and you add OB that catches 80% of the players, then only 10% of players will get a 3. That's not enough to continue calling 3 an expected score, so par should be raised from 3 to 4.
If you raise the average score by 0.3 on all holes, there are bound to be some holes that will be pushed over the threshold to a higher par. Probably 5 of them.
(This is similar to one of the criticisms of close range par. In general, the intended flight paths should be used to set par. But, if an intended flight path is so unlikely or unforgiving that hardly anyone actually plays it that way, then it shouldn't be the basis for par. With that modification in mind, then CRP will also increase the total par on your OB-licious course by about 5 throws.
And, while we're on the CR Par subject, I think Close Range is where a player can expect to get up and down in 2, i.e. a little more than half the time. Which can be about 280 feet for Open players.)
P.S. I can't wait to see what acronym you come up with that spells out JOHN MATLACK in honor of the great round that started all this.
Chuck, let's get the first significant digit right before we try for the second.
