Anyone who reads either this blog or The Art of Education, knows I am a big advocate of growth mindsets and the potential impact "get better" thinking has on student achievement. This is one reason why having a growth mindset is one of the seven principles of Thrivapy. One of the many reasons why I encourage "better" thinking over "be the best" thinking is how well "better" relates to developing ownership and responsibility (taking ownership is also one of the seven Thrivapy principles).
"Be the best" thinking depends on comparing one's performance against another group or another individual. As a former athlete and coach, I have no problem keeping score to measure wins and losses, but when it comes to personal development, which is what school is supposed to support, measuring against others to determine gains presents an obvious problem - you have no control over how well someone else performs. You only can control your own efforts. Measuring against someone else not only can make a great effort on your part seem less important than it really is, but having another person in the equation provides a student with an easy excuse for their performance, especially if it was less than satisfying.
Excuses are "anti-ownership missiles"!
If you want to build ownership and responsibility, try "better" thinking. Using this mindset, there is only the student and her efforts to evaluate progress. Progress is measured purely against one's own results over time. If things go well and progress is seen, it is easier to highlight that progress without another's "score" visible. If things do not go as well as expected, there is no built in excuse to deflect responsibility.
Learn from the experience and try again with a new lesson learned and a better ideas of how to be more successful next time.