Every finite extensive-form game with perfect information has a subgame-perfect equilibrium. In this note we settle to the negative an open problem regarding the existence of a subgame-perfect <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$$\varepsilon $$</EquationSource> <EquationSource Format="MATHML"> <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mi mathvariant="italic">ε</mi> </math> </EquationSource> </InlineEquation>-equilibrium in perfect information games with infinite horizon and Borel...</equationsource></equationsource></inlineequation>

We show how a stochastic variation of a Ramsey's theorem can be used to prove the existence of the value, and to construct [var epsilon]-optimal strategies, in two-player zero-sum dynamic games that have certain properties.