If you’re failing in a performance, perform differently, don’t try to perform better.
Doing the same thing again and again while expecting different results is the definition of insanity. Don’t allow yourself in a fencing tournament to get caught trying to apply the same strategy over and over again against the same opponent if it’s not working. This may seem self-evident but it’s easy to take this attitude, which is a good one in a practice situation, and fall into the same bad pattern over and over again.
In practice, it is beneficial to take a technique that you are working on perfecting and apply it to the same rigours again and again. This allows you to get coaching and make the small adjustments needed to make it successful.
However in a tournament or other ‘applied’ environment, it is essential that you realize that the technique you have attempted to apply is not applicable or good enough at this time (even if it was earlier or yesterday or against a different opponent). You then have to use your mental presence and discipline to change strategies.
Make sure that part of your practice is to give yourself regular space to look back on your fencing (from a safe distance of course) and review whether you’re succeeding or caught in a ‘make it better’ rut.