Garry Kasparov vs William James Sidis
Garry Kasparov (IQ 190) vs William James Sidis (IQ 250). Side-by-side comparison of intellect, achievements, era and cultural impact.
| Born | 1963 | 1898 |
|---|---|---|
| Died | — | 1944 |
| Country | AZ | US |
| Estimated IQ | 190 | 250 |
| Best known for | Being the top chess player from 1984 until 2005 | The Animate And The Inanimate |
Who had the higher IQ?
By the most cited estimates, William James Sidis tops this matchup with an estimated IQ of 250, a 60-point margin over Garry Kasparov (190). IQ estimates for historical figures are reconstructions, not test results — they sit on top of biographical evidence, productivity, and the difficulty of the problems each person solved. Treat the number as a directional signal, not a verdict.
Achievements compared
Garry Kasparov is best known for: Being the top chess player from 1984 until 2005 William James Sidis is best known for: The Animate And The Inanimate
Different eras, different boards
The two were born roughly 65 years apart (1963 vs 1898), which matters: scientific tools, available knowledge, and intellectual culture compound. Comparing minds across eras is comparing players on different boards.
The verdict
So who was greater? The honest answer: they're not strictly comparable. By raw IQ proxy, William James Sidis edges out. By measurable, lasting influence in their respective field, both are anchors of the human record. If you have to pick one to bet civilization on, pick the one working on the problem you care about.