Okay, can someone help explain the handicap system, course rating and slope?  What I'm having a hard time understanding is why I have a 12.7 handicap but shoot in the high 80's to low 90's on average.  This makes it difficult when I play with others and I tell them this and shoot 95 when they think I should 83.  I probably have gotten lucky and shot an 83 or better just a handful of times.  

Is there an easy way to adjust what my handicap should be based on the courses I play?  It needs to be fairly simple since I'm not much on carry a calculator on the course.  Even though it probably would not be a bad thing to start based on some of the scores I post.

Any feedback I can get to better understand this system would be great.