What Expert means on this site
Expert is a transparent product label, not a claim of master-level play. The engine searches one ply deeper than Hard and uses a larger node budget, which helps it see more exchanges and short tactical sequences. It remains a small JavaScript opponent running entirely on your device; it has no opening book, cloud analysis or calibrated Elo.
Give calculation enough clock
Use 15+10 when the goal is serious practice. Establish the position's demands first, calculate forcing branches and stop when further thought is unlikely to change the decision. Expert replies quickly because calculation happens locally, but you should not copy that tempo. Your clock is a budget for the difficult choices, not a speed contest with the processor.
Turn the game into a diagnostic
After the game, classify the critical moment as tactical vision, calculation depth, evaluation or clock allocation. Note the position and the time you had left, then test the same thinking process in a later session. If the engine's move seems strange, treat it as a candidate to investigate rather than an authoritative verdict.