Engine drill
Drill: win the Lucena (rook and pawn)
Escort the pawn past the checks.
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White to move
Rook and pawn versus rook — the Lucena win. Your pawn is one step from queening, but your own king blocks the square and Black checks from the side. March your king out toward your rook; when the checks come, block one with your rook (the 'bridge'), and shepherd the pawn home. Promote to win.