Opening explorer

• 4.O-ORuy Lopez: Berlin Defense55.3%white, 4,084 games57.7%white, 20,805 games57.5%white, 13,685 games54.0%white, 29,270 games
• 4.d3Ruy Lopez: Berlin Defense, Anti-Berlin Variation6 named lines below6 named lines below6 named lines below6 named lines below
• 4.d41 line through here1 named line below1 named line below1 named line below1 named line below
• 4.Nxe5Ruy Lopez: Halloween Attack1 named line below1 named line below1 named line below1 named line below

Moves come from the 3,810 lines we replayed and validated. Win rates exist for the 314 we sync statistics for, so the deeper you go the more often you will see a name without a number.