From Descriptive to Algebraic Notation
Algebraic notation, the system of naming every square uniquely (e4, Nf3, Rxd5) that every modern player learns, was invented by Philipp Stamma as early as 1737. English-language chess publications, however, stuck with descriptive notation, where a square's name depended on which side was moving, well into the 1980s. FIDE formally adopted algebraic as the global standard in 1981, but did not make it mandatory for recording moves until July 1, 1997, a remarkably slow transition for a change that seems obvious in hindsight.
Why descriptive notation was so confusing
Descriptive notation named squares from each player's own perspective, so "King's Bishop 4" (KB4) meant a different physical square depending on whether White or Black was moving. The same opening move that algebraic notation calls 1.e4 became "P-K4" for White and, from Black's reply, "P-K4" again for an entirely different square, an ambiguity built directly into the system's design rather than an occasional edge case.
A 250-year head start nobody used
Stamma's algebraic system existed from 1737, and gradually became standard in German and then Russian chess literature through the 19th century, but English-language publishers kept using descriptive notation for another century and more after that, a genuinely long-lived case of an objectively less ambiguous system losing out to institutional inertia and familiarity.
Why the US Chess Federation finally pushed for change
In the 1970s, the US Chess Federation began actively campaigning to convert American chess to algebraic notation, for three concrete reasons: US chess books would gain access to the larger international market already using algebraic, the system produced fewer irretrievable or ambiguous game scores, and it took up meaningfully less space on the page, letting publishers fit more games into the same number of pages.
FIDE's two-stage adoption
FIDE adopted algebraic notation as the official global standard in 1981, but only made Standard Algebraic Notation mandatory for recording tournament games starting July 1, 1997, a sixteen-year gap between "this is now the standard" and "you are actually required to use it." That gap reflects how much lingering, older-generation attachment to descriptive notation FIDE had to work around even after formally settling the question.
Try it yourself
If you have ever picked up an older chess book and found "P-K4" instead of "e4," you were reading pure descriptive notation. Try transcribing a short, famous game's opening moves from algebraic into descriptive notation by hand, the exercise makes it immediately obvious why the switch eventually happened: descriptive requires you to track whose perspective every single square name is coming from, move by move.