Other commenters have mentioned marginal utility, but this article is basically explaining minimax [0] decision making - people (and chess AIs) tend to pick the

Other commenters have mentioned marginal utility, but this article is basically explaining minimax [0] decision making - people (and chess AIs) tend to pick the option that minimizes worst case losses. [0] https://en.wikipedia.org/wiki/Minimax https://en.wikipedia.org/wiki/Minimax