A common debate in all media circles, whether an average score should be a 5, or a 7. Usually this falls into two standings, one being it should be objective and that a 5 would be bland, not good enough to recommend, and that a 7 would be the average, the other seeing it subjectively and that 5 should be the average of what you've seen before, and building your other ratings around that.
I've followed both systems in the past and have always felt limited in how I place a show into these 10 scores. Following the 7 average, I could only rate a good show from 7-10, and so I switched to the 5 average, which expanded my range a bit to putting good shows on a 6-10, but then you get hit with a show that straddles between to numbers and neither one represents the score you want to give it. So what's the next step? To tip the scale over.
Unless you're a reviewer with no preference, it's natural to watch more shows you enjoy than shows you want, and so I believe your rating system should reflect that. What's common in both objective and subjective rating is that 5 (Technically 5.5 I guess since we can't rate 0's) is the point where the good and bad are equal, in case of objective, the contents of the show, and in case of subject, the comparison to other shows. Why dedicate though half your scale to rating bad shows when you watch good shows more often than not? After getting fed up with this I decided to compress my bad scores to let my good scores breath more. With this, my average moves to a 3, giving me either a 1, or a 2, which is all I need really. I'd rather spend time thinking about how good a show is, than how bad a show is. With this, I now have the range of 4-10 to place where I feel on a show I enjoyed, nearly double the options I had in either of the other two systems.
Rating - Description % Good/ % Bad (Rough guide)
10 - Masterpiece 100/0
09 - Amazing 99/1
08 - Great 95/5
07 - Solid 90/10
06 - Good 80/20
05 - Nice 70/30
04 - Not Bad 60/40
03 - Average 50/50
02 - Bad 25/75
01 - Shit 0/100
Comparing my rating distribution to the global average, you can see that both have 40% of the scale containing only 10% of the total scores (1-4 on the global, and 7-10 on mine). The advantage with mine is that I use my less frequent scores for shows of high enjoyment and quality rather than of high disappointment and garbage. I essentially reserve 10 for my most favourite tv show and movie, when really it's practically on the same level as a show rated a 9 because I have the room to do so without crowding my other scores. Now, I can easily decide what to rate a show and be confident it belongs there.