Every ones ability to temporarily adapt to altitude is very different and has nothing to do with sea level conditioning. There is a standard deviation bell curve of where most people start to feel altitude in a negative way, and for me it was sometimes as low as 4,500', wheras some can go right up to 14,000' but I think its hard to do that without a very unusually high oxygen capability, more than a normal person has. So I believe most of the older books at lease councelled that going to 10,000' was probably the most one should shoot dor in a day, and then you can add 1,000' per day of sleeping altitude after that. You should climb to points higher than you will sleep during the day and then come down to sleep.

A 1500' DROP IS CONSIDERED ADEQUATE TO SAVE A PERSON FROM HAPE. If a party member has to go down with someone, generally 1,500 feet is eough, so always climb higher and sleep lower, this is one of the reasons for advanced camps going up Everest.