The Lucena position

I just learned about the Lucena position yesterday. I was practicing against the computer and in one trial the position turned into a queen versus rook endgame. While this is still winning for the stronger side, it’s not easy for me to play. I was wondering if there is a way for the weaker side to force a queen vs rook endgame or if I just messed up in that particular trial. Unfortunately I didn’t save the moves.

You messed it up that time. You sacrificed the rook in order to promote the pawn, which is not how it's meant to go.

Thanks. It only happened once so I thought as much. But I wanted to check with someone with more experience.

The bridge is built on the 4th rank. If it’s built on the 5th rank the weaker side can try R vs. Q by attacking the R with the King there.

Bad news: The stronger side can still go back with the R and try to win keeping the pawn.

Hi Sargon. I think I know what you mean. Sometimes the engine tries to attack my rook with its king when my rook is on the fourth rank. I haven’t completely analysed what should happen but I seem to find a way to win when the engine does that, (unless I blunder which happens sometimes).