The One-Syllable War

What actually happened

John Kelly's 1956 paper connected information theory to bet sizing: wager to maximize the growth rate of wealth and you can't be beaten in the long run. Shannon championed it; Thorp used it in casinos and markets; it became the quiet sizing rule of a generation of quants.

Paul Samuelson's objection was real: maximizing growth rate is not the same as maximizing your utility, and the 'long run' can be longer than your life. After years of arguing, he published 'Why we should not make mean log of wealth big though years to act are long' (Journal of Banking & Finance, 1979), every word one syllable, to be sure, as he put it, that the point could not be missed.

Both sides were right about different questions, which is why the fight never ended.

The play to remember

The sizing of a bet matters more than the picking of it, and even correct formulas embed assumptions about who you are.