One idea I taught was the importance of regaining presence and clarity of mind after making a serious error. This is a hard lesson for all competitors and performers. The first mistake rarely proves disastrous, but the downward spiral of the second, third, and fourth error creates a devastating chain reaction. Any sports fan has seen professional football, basketball, and baseball games won and lost because of a shift in psychological advantage. People speak about momentum as if it were an entity of its own, an unpredictable player on the field, and from my own competitive experience, I can vouch for it seeming that way. The key is to bring that player onto your team by riding the psychological wave when it is behind you, and snapping back into a fresh presence when your clarity of mind begins to be swept away.
With young chess players, the downward spiral dominates competitive lives. In game after game, beginners fall to pieces after making the first mistake. With older, more accomplished players the mistakes are subtler, but the pattern of error begetting error remains true and deadly.