Football cake

Looking at this football field cake, you can see the amount of work that goes into this piece. But on closer examination it becomes clear that the person doing the decorating was not a football fan, or at least doesn't understand the numbering scheme on the field. The regulation field goes from 10 to 40, with 50 in the middle then back down again. This field however increments by 10 all the way up to 90, up and down on both sides. I wonder why this cake hasn't sold yet.