The pride and sorrow

Not once, not twice, but three times an American chess player as seemingly come out of nowhere, shown himself to be (arguably) the best in the world, and then abruptly retired.

The first two are the well-known Paul Morphy and Bobby Fischer. The third I argue is the computer Deep Blue, which after defeating Kasparov, was disassembled by IBM without any chances for additional challenges by other humans or other computers.