Alright. No obvious legends this time.
Hint 1
This grandmaster was never ranked World No. 1 and never played a World Championship match, yet they won one of the strongest tournaments in chess history by finishing ahead of multiple World Champions.
Hint 2
They made lasting contributions to opening theory. One opening variation still bears their name, although most club players know the opening better than the person behind the name.
Hint 3
Although they defeated many of the greatest players of their era, they died before turning 50, leaving many to wonder how strong they could have become.
Who is the grandmaster?
No bonus hints this time unless you completely exhaust your guesses. This one is genuinely difficult.