What is the 'Starting Value' in gymnastics and why is it different for each gymnast?

This is they way in the Olympics

With the difficulty of your skill(vault) or the combination of all your skills(beam,floor,and bars) you come up with a start value on difficulting(such as a 6.6) then a 10.00 is added with a 'Starting Value' of 16.6 then to get your final score they deduct the points and then you get your end score.

Answer

Each element in a routine is categorized by difficulty, in sections A-E, with A being the simplest, and E being the most difficult. The starting value is the summation off all of these skills' Degree of Difficulty score.

Answer

For most compulsory gymnasts the starting value is 10.00. But the more elite the gymnast the more variations there will be within start values. Say there is a college gymnastics team and one girl is going to only do a front handspring on the vault (which is a very simple skill) and another girl is going to do a tsuk (a very difficult skill) it would not be fair for the judge to base both vaults off of a 10 because the front handspring should be absolutely perfect. So because the front handspring is an easier skill it has a lower start value.

Answer

The other answers are pretty good but what pretty much how a routine is scored.

There is there is an A and a B judge. The A judge adds up certain points (that are known to all gymnasts and coaches) for each skill that is completed sucessfully. The B judge score out of ten and deducts for any mistakes i.e. falls, wobbles, extra swings/steps, bent arms/legs, low landings, "closed shoulders, incorrect body positions etc.These to scored are then added together to give a final score for the gymnast. On vault a score is tabulated for each vault and then the average is found( at major competitions and the Olympics). On other occasion the higher score is taken.