25 years ago, Deep Blue beat chess world champion Garry Kasparov for the first time. I remember in high school the new chess computers (which were expensive) could play a solid 1400 caliber game, about where a decent high school player could compete and strong club players would scoff at the idea of even training with a computer. (There's no flair, no intuition!) Now computers are pretty much required for even semi serious players working on their games and an internet engine can crush a grandmaster.
Here is an interesting article
about how computers have changed the chess world in the last quarter century.