Chess School Quiz Challenge #14

Challenge
With f2-f3, White has prepared to expand in the center with e3-e4. How should Black react?
Solution
Black should quickly put a pawn break into action to put pressure on the white center before White can calmly expand.
1…c7-c5! was the right move that IM Jonas Roseneck played in this game from the 2023 German Masters against GM Michael Prusikin.
White is not just planning to take control of the center with e3-e4. Prusikin had a second option in mind. White could also postpone e3-e4 and play b2-b4 first. That would prevent the black pawn break.
Black would be left without counterplay and would have to watch as White takes control across the board. That's why it's so important to intervene with 1...c7-c5.