We are going Dec 11-15, the CL has increased for each day in our chosen parks. However, I've reviewed our TP and there aren't any changes to our wait times. What is going on?
I went in the early park of December this past year. The longer/adjusted wait times didn't start showing up in my plans until a couple months before hand. It was still in time to make changes before making FPP reservations so I didn't worry about it too much.
Did you see this?
No, I hadn't seen this. Great article to read.
Did you hit "Evaluate"? That will re-run your TPs and may change wait times also. Because overall given the adjustment CLs will generally decrease this year, so if your numbers go up that reflects an increase in anticipated wait.
The CL has always been a relative comparison, not an absolute number. In the "old days" TP used a linear scale. They looked at the whole year and the least crowded 36 days would get a 1 rating, the 36 most crowded days would get a 10 rating, and the others would all be divided more or less equally. Several years ago they went to an algorithm based on a "normal distribution curve" that said that 5 and 6 days would be the most numerous, and the number of days in each category would trail off to 1 in one direction and 10 in the other direction. The purpose of this was to make the really high and really low number days "more meaningful". But the overall increase in the number of people coming to WDW caused the "nornmal" curve to skew to the right; there were more 8 and 9 days than 5 and 6 days, so they readjusted the algorithm so that 5 and 6 days were once again in the majority.
What does this mean practically? in 2017 a 6 day will still be more crowded than a 3 day and less crowded than a 10 day, but because there are just more people every day, wait times for a 6 day in 2017 may be longer than they were on a 6 day in 2015 or 2016. Same number of rides, plus more people, equals longer lines. The 2017 CLs will still be valuable in comparing relative crowds in 2017, but will likely not lead to absolute comparisons to past years.
But are attendance levels really a normal distribution? If not, forcing the crowd levels into one actually distorts the results presented. Say (for simplicity), most days WDW has 8,000 guests. On a few empty days, they have as few as 1,000, while on the most crowded days they have 10,000. The average days (8,000 guests) shouldn't have a "5" rating, because then the busiest day (which gets a 10) and the least busy day (which would get a 1) would both be 5 levels from the average, even though one is much, much closer in terms of actual numbers. In other words, I don't care (and I don't think most users care) about the actual number of their day - what matters is the differences. If a bell curve and calling the average a "5" regardless of the distribution is artificially forced onto the numbers, then the differences between numbers are variable and therefore not very meaningful. In other words, a difference between a 1 and a 3 would be significant, while the difference between a 4 and a 6 would not. IMHO, a difference of 2 levels should be equivalent to any other difference of 2 levels.
I actually agree with you completely. Whether it's coincidence or not I don't know, but it was right around the time they switched from the old linear system to normal distribution system that I started losing faith in their numbers. The old system seemed to work, and it was simple enough that you didn't need a math degree to understand it. "Theoretically" I understand the new system, but I don't think it's any more "accurate" than the old one.
But one thing that has always been true and that a lot of people still don't understand is that the CLs are relative within a year. There is no mathematical validity of comparing a CL7 between years.