Double-spending is the result of successfully spending some money more than once. Bitcoin protects against double spending by verifying each transaction added to the block chain to ensure that the inputs for the transaction had not previously already been spent.
A Payout of 0.1709 BTC was used to cover unpaid losing bets 1GJfAJ3uD7h4Vr8Z3SQqu4x6Ygz2zGXwPn and 19FjAnt8an6jDaZN2mTqrca4Hj4iA6KkBa that were double spent