Challenge #1

Imagine a system that forms ordinal numbers as follows:
first := suppletive
second := after one (could be suppletive as well)
third := after two
fourth := after three
...
The origin for this system is along the line of specifying the position in some line-up: the one after five others is obviously the sixth one. The numerals may have congruence or some such to mark gender or class agreement with the noun - class agreement along the lines of Chinese would probably work out really well with this.

This may later grammaticalize, and the morpheme marking "behind" (as well as the class marker) may merge into the numerals. In this case, we would obtain a system where each ordinal is offset by -1 compared to the corresponding cardinal.

The challenge itself:
Come up with a reasonable and likely development of a system where the offset is +1 instead. Extra challenging would be reasonable systems with an even greater offset in either direction.

An obvious attempt would be to use "before three" to mark the second, but this doesn't make logical sense: there is no guarantee the n:th element will be part of a group of n+1 things.

Contribute through the comment-field if you have an idea.