Concealed Hand poker
A hand played in such a way that you would not suspect it of
being very good, but that turns out to be so. For example, if,
in lowball, two players kept raising each other back and forth,
and a third just kept calling all the bets, you might suspect
that he was drawing one to a good hand. If he turned out to
have a pat wheel, that would be a concealed hand. In any poker
game, if one player lets the others do all the betting for him,
usually
because the situation allows him to just keep calling without
ever having to make a raise or leading bet of his own, and that
player actually holds a hand that cannot lose, he is said to
have a concealed hand. Also called hidden hand.