Cyphers II

So this morning someone posts up some suppositions and this chart..

let's see what we can eliminate...

1. chances are it's not a simple ceasar shift. the freqs don't work out.
2. chances are the PT alphabet is spread across the whole range of 00-99, and not rotated (i.e. 00-25, then 26-51, etc). still could be simple substitution cipher.
3. it's not viginere, as it requires a key and he said there was none.
4. it's not playfair or any other polygraphic, as he said 2 digits = 1 PT character

This made me realize how close he was to getting it right, if he realized he was shifted one letter high he would have it. so I was thinking, what if instead of going 0-9 both horizontally and vertically we used 0-9 horizontally and 9-0 vertically.
I.E.

x 0 1 2 3 4 5 6 7 8 9
9
8
7
6
5
4
3
2
1

This would mix up the order enough to throw off anything so simple as someone just writing 0=a 1=b 2=c ect.

In regards to it not being playfair, its funny because I originally based it off of a cypher in a book I read (I'll find it later and give up the title), that claimed it was a playfair cypher.