Checkers Solved?

Does anyone understand the claim being made here in this New York Times article? There is some sense in which the creators of the Chinook checkers-playing program have shown that Chinook cannot ever lose at checkers, but the article includes the caveat:

Even with the advances in computers over the past two decades, it is still impossible, in practical terms, to compute moves for all 500 billion billion board positions. Instead, the researchers took the usual starting position and then looked only at the positions that would occur during the normal course of play.

Do they mean that from the normal starting position that Chinook cannot lose? Or does checkers have stylized openings the way chess does, and they mean that Chinook cannot lose from any of those openings?