Training exercise 32056

The exercise marks wrong an answer when it is as good as the one qualified as "best move":
White plays 1. R X b7+, answer black K X b7. So far so good. Then I reply Q X d7+ and the program says "Good move but you can do better". Why?

I think your move leads to a mate in 7 and Qd5 leads to a mate in 5. That is probably the reason.

Maybe posting the link here so we can easily watch the puzzle would help. I would try solving it and after it we could break our mouses together

ManuelASdlM it's because of the a5 square. It makes it mate in 2 extra moves because you have to chase the king into and off of a5 if you take the knight.