Let $\mathcal{D}=(d_n)_{n=1}^\infty$ be a bounded sequence of integers with
$d_n\ge 2$ and let $(i, j)$ be a pair of strictly positive numbers with
$i+j=1$. We prove that the set of $x \in \RR$ for which there exists some
constant $c(x) > 0$ such that \[ \max\{|q|_\DDD^{1/i}, \|qx\|^{1/j}\} > c(x)/ q
\qquad \forall q \in \NN \] is one quarter winning (in the sense of Schmidt
games). Thus the intersection of any countable number of such sets is of full
dimension.
For any $i,j \ge 0$ with $i+j =1$, let $\bad(i,j)$ denote the set of points
$(x,y) \in \R^2$ for which $ \max \{\|qx\|^{1/i}, \|qy\|^{1/j} \} > c/q $ for
all $ q \in \N $. Here $c = c(x,y)$ is a positive constant. Our main result
implies that any finite intersection of such sets has full dimension. This
settles a conjecture of Wolfgang M. Schmidt in the theory of simultaneous
Diophantine approximation.