At the end of the ScalaCheck user
guide<http://code.google.com/p/scalacheck/wiki/UserGuide>you have a description
of the command-line arguments:

-minSuccessfulTests, -s: Number of tests that must succeed in order to pass a
property

And now for a bit of self-promotion :-). If you use specs2 <http://specs2.org>,
you can set the properties for each example, directly in the code
<http://etorreborre.github.com/specs2/guide/org.specs2.guide.Matchers.html#Setting+the+ScalaCheck+properties>:

"this is a specific property" ! check { (a: Int, b: Int) =>
(a + b) must_== (b + a)
}

Eric