Josh's Academy, Intro Mastery Quiz, Page 14

[RMacready]

Hello -

Has anyone noticed that in Josh's Academy, introduction mastery quiz, page 14, where he asks white to find mate in five (white has a King on a8, and Rooks on a1 and b6, and black has a King on g5), that it is definitely possible to do better? I tried to move Rf1, which I am quite certain would have resulted in a worst case of mate in 4. But the tutorial would not allow it, saying it wasn't the best move. Is Josh's approach somehow more tactically sound, or is this just an oversight?

[RMacready]

Hello -

Has anyone noticed that in Josh's Academy, introduction mastery quiz, page 14, where he asks white to find mate in five (white has a King on a8, and Rooks on a1 and b6, and black has a King on g5), that it is definitely possible to do better? I tried to move Rf1, which I am quite certain would have resulted in a worst case of mate in 4. But the tutorial would not allow it, saying it wasn't the best move. Is Josh's approach somehow more tactically sound, or is this just an oversight?

[Swordfishtrombo]

That does indeed look like an error in the quiz - Rf1 does lead to a forced mate in four, as far as I can see it.