puzzle 61920

Solution of puzzle is Rd3, but Rg3 seems perfectly valid to me. How lichess take consider of multiple solutions ?

Nxg4 attacks queen after Rg3

Rd3 is better because after ...Nxg4, the g file rook can capture while the d file rook maintains pressure on the queen.

If Rg3 Nxg4 Rxg4, black's queen can slip away

And even though Rg3 wins a piece, it's still not enough for an advantage since white was down a piece at the start of the puzzle.

You can press space after the puzzle to start computer analysis and see why the alternatives are worse.

Thanks for your answers ! I had missed the Nxg4 problem.