Can you please explain "the transfer function is negative"?

I'm wondering whether one has tested with the same model but on two situations:

1) Bring it to superhuman level in game A and then present game B, which is similar to A, to it.

2) Present B to it without presenting A.

If 1) is not significantly better than 2) then maybe it is not carrying much "knowledge", or maybe we simply did not program it correctly.