1. Rc1 Kb7 2. Rc4 Rf1 3. Kd7 Rd1+ 4. Ke6 Re1+ 5. Kd6 Rd1+ 6. Ke5! Re1+ 7. Re4 Rxe4 8. Kxe4 Kc7 9. e8=Q ...
It starts off with 1. Rc1. The king has several options, but the most sensible one is 1. ... Kb7. (The naive 1. ... Kd6 gives White a quicker tactical shot at queening.) White follows up with 2. Rc4, and Black has no choice but to simply move a random piece, in this case 2. ... Rf1. The rook is unable to prevent the king from moving (which allows the pawn to promote), for if he moves to the d file, the king will simply escape through the f file.
The king then moves out to d7 to allow his pawn to promote. The rook checks the king with 3. ... Rd1+. White moves to the e file (but still out of the pawn's way) with 4. e6. Black once again checks the king with 4. ... Re1+.
The king moves to d6, and the rook checks him with 5. ... d1+. The king moves out away from his pawn to e5. The rook once again checks with 6. ... e1+, and White counters with 7. Re4. Black exchanges rooks (7. ... Rxe4 8. Kxe4) and Black is now unable to prevent the pawn from promoting.
Black moves his king with 8. ... Kc7, and White promotes, putting him in a position to easily checkmate the Black king.
The Lucena Position teaches a rule of thumb for rook-and-pawn endgames: the opposing king must be at least two files away from the promoting pawn. Otherwise, the promoted pawn would be taken.
1. ... Kd6Edit
This variation is disastrous because it lets White slip his king off the e8 promotion square in such a way as to avoid check. The continuation:
- Rc1+ Kd6
- Kd8 Re2
- Rd1 Kc6
- e8=Q Rxe8
leaves white with an elementary King and rook versus king mate.