Ever since the rules of modern chess were first codified in the late 15th century, players and theorists have debated the correct way to open a game. In the centuries since, many openings and their subvariations have been explored, and even today in the age of computer databases, new ways of playing the opening are still being discovered. Some openings come and go according to the whims of fashion - or because an antidote has been found that has rendered them dubious or outright unsound - but others have remained perennially popular and will likely never be refuted.
Of the many ways of starting a chess game, 1.e4 has been the most popular ever since the earliest recorded games - indeed, the oldest known recorded game of modern chess, recorded as a poem in 1475, begins 1.e4. For most of the early centuries of chess, chess theory largely focused on the Open Games, starting 1.e4 e5. Although most of the popular modern openings such as the Sicilian Defence, the French Defence, and the Caro-Kann were known back then, it wasn't until the mid 20th century that replies to 1.e4 other than 1...e5 began to increase in popularity. In this series of tutorials, we will be looking at the major chess openings starting with 1.e4