How to learn about opening theory in chess?

How has chess opening theory improved over the past 30 years?

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• Answer:

  Good question! The invention of computers that fit inside your house ( thank you Mr. Jobs) , the internet, and chess engines have drastically improved opening theory in several ways.  Several decades ago, chess players were dependent on magazines and books to catch the newest developments in opening theory. Thanks to the internet, we can now follow high level games in real time and it is very common for opening theory to evolve/change in the middle of a tournament.Opening databases also allow anybody to store literally millions of games on his/her PC. Imagine having to sift through thousands of pages of literature to keep up with theory! Thanks to programs such as chessbase you can simply input a position, instantly see all the high level games where said position has been reached and the win/loss/draw percentages.  Chess software is a wonderful aid to an opening theoretician. Programs tend to be very materialistic and tactically flawless. Many gambit lines once considered dangerous have now been "defanged" as engines have helped us figure out how to grab material and hold onto it without getting checkmated.