Although it is not trusted by most elite players, it has not been refuted and some very strong grandmasters have played it. The Albin Countergambit (2...e5) is generally considered too risky for top-level tournament play. Similarly, the Marshall Defense (2...Nf6) is very rarely seen in grandmaster play, as most theoreticians consider it definitely inferior for Black.
Although it is not favored by most top players, it has not been disproven and some very skilled grandmasters have employed it. The Albin Countergambit (2...e5) is generally regarded as too hazardous for high-level tournament competition. Similarly, the Marshall Defense (2...Nf6) is rarely observed in grandmaster play, as most theorists consider it undoubtedly weaker for Black.