Clear jaw lines simply mean... 

that the person keeps everything to himself and is good at keeping secrets.

 

But a person with prominent jaws means, he is... 

destructive,

 stubborn,

 vindictive, 

and very selfish. 

 

And it is difficult to be friends with him... 

because he hides his feelings 

(does not show them to others).

And is in competition with others all the time.

 

And has tendencies... 

to destructive towards things beyond reasonable control.

 

Regarding the issue of chances of luck... 

The chances of luck are good before the age of 30 and average between the ages of 30 to 50 years.

 

 While a person  with a fat chin may obtain wealth in old age.

 

 While a person  with a thin and bony chin is at risk of ending his life... 

Loneliness and bankruptcy in advanced ages.