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Once you have your candidate moves, you need to calculate with the opponent in mind. This is where most calculations break down. GM Grigor Grigorov identifies a central problem: “A typical mistake when calculating is to not look for the strongest moves for your opponents.” To fix this, adopt a proactive, skeptical mindset.

If you missed a defender's resource, highlight that specific node.

Most training PGNs just show full games. The uses:

When you study your new PGN database, you will occasionally find that:

Copy the text below and save it as a .pgn file to start building your calculation library.