It seems to me that most of the arguments against the data in this thread are due to the comparison between AD&D1 and D&D3. Had I just listed the level advancement for the AD&D1 party through the adventures, most everyone would have just nodded their heads and said, "Yeah, that's about right."
I mean, after all, the data/calculations on the party's level advancement pretty much completely follows what the author (Gary Gygax) seemed to expect, predict, and plan and design for. He wrote these modules to follow one after the other (the original "adventure path"), and the party comes out of one adventure at pretty much perfectly the appropriate level for the next adventure in the series.
I find it funny that instead of folks saying, "Well, of course, Papa G planned it that way," folks are saying, "Impossible, your numbers must be wrong." I guess folks didn't have much faith in Gygax that he knew what he was doing when he "placed xp" in the adventures and planned the next adventure.
To be honest, I didn't have faith that Gygax planned it that well. But I learned that he apparently did at least put some thought into the xp to be gained in each adventure. The level advancement rate works perfectly through the series.
If the PCs didn't advance at least close to what is shown in this data, they wouldn't be powerful enough to take on the next level of the dungeon or the next dungeon in the series. Essentially, the series -- written by the game system designer, himself -- wouldn't work the way they were planned to follow.
But then also remember, that through many levels in AD&D, the xp needed for a level is double that needed for the previous level. So, in many cases, even if you cut the xp gained in half (50%), the level difference would only be one level.
I really should not have presented this data as a comparison between AD&D1 and D&D3. I should have merely presented the data on just AD&D1. There wouldn't have been nearly as much argument.
For instance, check out the answers in this thread:
http://www.enworld.org/forum/general-rpg-discussion/243299-party-comes-out-other-side-t1-4-will.html
When asked what level PCs come out of ToEE, the answers all match what my data in this thread showed. Ironically, those anecdotes were accepted without argument, but my hard data -- showing the exact same answer -- is considered suspect.
Something I take from what the data and calculations here show, is that Gygax planned pretty darn well for the levels his adventures would produce. I find it somewhat humorous that so many people are essentially arguing that, no, Gygax was wrong, the adventures cannot produce the levels he planned for the next adventure in the series.
Quasqueton