It's Official: 179 GMs by 1978

Continuing with Titled Players, Sizing the Data, the next step is to compare FIDE's 1974 data with Elo's 1978 data. To keep the numbers manageable, I'll limit myself to looking at GMs only. The goal of this exercise, after all, is to determine how many chess grandmasters there have been since the beginning of recorded history.

1974:   91 GMs
1978: 178 GMs

Keeping in mind that the Elo's 1978 data was a list of all titleholders, the difference of 87 GMs would be partly due to inactive GMs no longer on FIDE's 1974 list, and partly due to GMs minted after 1974.

First test: Are all of the 1974 GMs present and accounted for in 1978? To answer this question I created an ID for each player consisting of the first five characters of the player's last name concatenated with the player's birth year. Fischer, for example, is 'Fisch1943'. There are some unusual constructions like 'Tal, 1936', but my database has no trouble handling them.

Of the 91 GMs in 1974, I found all of them in 1978, with the exception of three. Using Gaige to resolve the discrepancies, I determined that two were because of an error in the birth year on the FIDE list. The third (Hecht, Hans-Joachim) was an error on ELO's list; Hecht was incorrectly identified as receiving an IM title in 1973, when it was the GM title he received that year. End result: I confirmed that there were 91 GMs in 1974, and that Elo should have listed 179.

Second test: How to account for the increase of 88 GMs from 1974 to 1978? This is easy to answer because Elo's list included the year that a player earned the title. End result: the 1974 list omitted 34 inactive GMs, while there were 54 names added during the years 1974-1977.

Incidentally, for anyone not familiar with the story, the first titled players were nominated by FIDE in 1950. Of the 27 GMs, nine were still active in 1974.