I keep hearing that but how can they base a crowd prediction on wait times in the future? Even a computer isn't good enough to see in to the future
I don't know if that prediction for January is right or wrong but I will say that a "1" does not exist anymore, in my opinion. At least not with the same definition that it had 2 years ago. The parks are never that empty now (baring weather like cold or downpouring rain). A 1 crowd level is probably more like a 4 from 2 years ago. I'm not expert, just my opinion.
I truly don't mean to start a debate about TP vs. Josh - both have their plusses and minuses, and many people are very happy with either or both. But even Josh predicts the future, in terms of which parks he feels will be most and least crowded months from now, and he makes recommendations about which parks are preferred. TP uses a lot of hard data and statistical forecasting, and Josh's is based more on personal knowledge and experience, from what I can gather. Both of them seem to be on target a lot of the time, and sometimes they miss, because, as you say, no one can predict the future with absolute accuracy.
And I agree that there are no more real "1's", like there used to be. I think TP adjusted their ratings to reflect that. If I recall correctly, they said that they rate the days on their relative wait times to each other. They gave the example one of having 100 marbles, each a different size, and sorting them by size and then grouping them by tens - the ten smallest, then the ten next largest, on up the ten largest. It doesn't mean that the smallest marble is the size of a pea and the largest is the size of a beach ball - only that those two are at the opposite extremes. They rate park wait times in a similar manner - the days with 1's are the days with the (predicted) shortest wait times of the year, and the days with 10's are those with the longest. That doesn't mean the 1's all have wait times of zero - just that they're the shortest in proportion to other days. And we all know that WDW is getting more and more crowded, with fewer really slow times. I think TP gets a bad rap sometimes because people don't really understand how they go about their ratings. It isn't about how crowded the parks feel or how many people are in front of you at the counter service restaurant. That's very subjective and will be different for various people at different parks at different times of the day. The wait times are something that can be measured absolutely and can, to a certain extent, be predicted based on history and hard data. And TP doesn't hesitate to adjust their park ratings if they come across new information or a better way of predicting. I personally would rather have them do that and make the ratings more accurate for the days I'm there than to go expecting a 2 and have it actually have turned into a 6, and I had no idea to expect that. I like that they update things. And on their blog every week, they take their predictions for the previous week and compare them with actual wait times, to see how they did. The vast majority of the time, they are spot on, and, if they missed by very much, they do their best to explain why they think that happened. I admire them for holding themselves up to public scrutiny like that. Josh may do this too, for all I know . I admit that I don't follow his site closely. I do know that many people use his predictions and swear by them.
All this is to say that both TP and Josh's site offer very good and usually very accurate information about which parks to attend on which days. Either one or both can completely miss with a prediction for a specific park on a specific day. They are good planning tools but should never be assumed to guarantee 100% accuracy.