High-stakes situations can be nerve-wracking. Among other things, this is due to the fact that the outcome is still uncertain. Under such circumstances, people are subject to tensing up and succumbing to fear -- both of which are generally ineffective mind states. To defend against this, cultivate the belief that you've already won and your opponent just hasn't realized it yet. This will allow you to act coolly and confidently -- which will increase your chances of success.