Formal titles began only in 1950, and international ratings in 1970. In Szen's era, international tournament competition was very rare, with long-distance travel being both cumbersome and expensive. The website Chessmetrics.com assigns retrospective historical ratings, using modern mathematical algorithms, based on available results.
Formal titles for chess players became standard in 1950, while international rating systems were established in 1970. During Szen's time, international tournaments were rare due to the logistical challenges of long-distance travel and its associated costs. The Chessmetrics website uses modern mathematical algorithms to calculate historical ratings based on available game results.