Could this be simplified by asking students what they think their score on the test will be and adjusting their final score based on how accurate that estimate

Could this be simplified by asking students what they think their score on the test will be and adjusting their final score based on how accurate that estimate was? Overall it seems like the biggest flaws in this system are that 1: Scores still get mapped to discrete letter grades. 2: A student's goal is not to get the highest score possible, rather it is to ensure that he or she is most likely to get an "A". For example: Given a 10 question quiz, a student who knows (in truth) she is 80% likely to answer each question correctly, and who needs to achieve a score of 0.2 to pass. The student is led to believe that by accurately estimating her confidence for each question at 80% she is giving herself the biggest advantage. If she does this and she gets 4 of the questions wrong her final score will be -1.219 and she will fail. However, if she had instead underestimated her confidence and given each question a confidence of 0.6 her final score would instead have been 0.290 and she would have passed. She could of course go even further and determine the likelihood of her getting N questions wrong and use that to determine the optimal confidence level to select which will maximize her expected score while ensuring that she is most likely to pass the class.