The Ruy Lopez: Berlin Defense, Anti-Berlin Variation, Mortimer Variation reaches a named position after 4 moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. d3 Ne7
In practical games, this line matters because the early pawn and piece choices decide which middlegame plans are natural. Use the board above to learn the move order, then run the drill without hints before adding the opening to your regular queue.
If this exact branch does not appear in your games, study the related variations below. Openings often transpose, and recognizing the family pattern is more useful than memorizing one narrow sequence.