Help me understand Rating/Slop/Handicap, my scores are always the same!

Ok, first I played a lot back when I was in HS 10 years ago.  I had an index of 10-12.  I just started playing again since HS and I have my Index down to 8-9.  My question is my scores should differ when I play different courses. Right?  But my scores stay the same. The easier or harder they are, my score does not change, or I play better at the more difficult courses.  I was off this week and here are the 5 rounds I played at 5 different courses.

    Rating - Slope - Par - My Score

1.  69          120     71        80                  

2.  69.2       127     72        79       

3.  68          117     72        81                  

4.  73          137     72        78

5.  66.4       111     71        80

I cant see why my scores are like this.  In my mind I should shoot better on the easier and I don't, I am the opposite.  Or do I just not know how to calculate what my HC should be at each course.

Well score 1 is my home course and I shoot anywhere from 75-81 consistently there ( my worst score since December is 83 and best is 72).  I was wondering if my home course should be re-evaluated or that score 4 is rated to high.  But that course is tough, has sand everywhere and some long holes.  I do hit the ball a good distance, driver 280, 7i 170. So does length make the course rank harder?  My home course is very tight, some fairways barely 15 yards wide with widest maybe 25 yards and lined with lots of trees.  The difficult course is basically wide open except for the bunkers.

yea its the Gambit Golf Course.  I went and played with the morning senior guys (was invited by a guy at my church).  They play the white tees.  Its very short around 5500 yards.  My short game killed me that day, could of easily shot around par. When I normally play with my regular group when we go playthere, we go from the blacks and its rated 72 slope  at 6700 yards.  Could there really be that much of a difference in the rating from one set of tee boxes? I know my short game is what kills me.

it was the course score 5 came from myrtlebeachgolf asked.  I guess my question now since thinking about it is how do they get the rating and slope of a golf course.  Why are 2 tee sets at same course so different?  How often do they have to recheck the course ratings?  It seems some courses I play I think are way harder than others, but according to the rating and slope they are suppose to be easier.

thank you for that link myrtlebeachgolf.  I understand it now.  I wanted to get down to scratch over the next few years, but according to that I will need to be shooting the ratings of the course, and with my local tracks all rated under par I have a tall task ahead.  Thank god for 12 hour work days and only 3 days of work a week.  I will have to def get my short game going.

k-troop you are right.  I have improved a lot over the last few months.  I have went to 3/4 choked down swing and take 1 club longer.  But yes I seem to get it closer from 135-175 then I can from 100 in.  Def ready for summer to practice, because when I'm one with my wedges, I can shoot close to par.