How can this puzzle have a 1866 rating?

I made many puzzles and must say they must do puzzles specialy for UB.

For UB the right solution is BxA6 and then after take Rook . Material in this situation is prioritized.

If Queen takes Pawn hanging you only defend with pawn to F3.

Second best is to take on A6 and then go to B7, forcing the Rook to move. But before that A Rook capture the F Rook from Knight.

I want ultrabullet puzzles please.

The puzzle did seem much easier than other puzzles of the same rating.