i was rating other maps a bit different too, for me 6 stars = normally, 7 stars = good, 8 stars = very good, 9 stars = excellent, 10 stars = impressively awesome.
and these 2 maps had 1 star for graphics too (then later they were overlapped with other ratings) : #22870, #22900.
maybe there were more of them, but that's all i saw