The opposite of "chalk up" is "write off." While "chalk up" is used to indicate a success or a victory, "write off" means to consider something as a failure or a significant loss. "Chalk up" is used to acknowledge a positive outcome, whereas "write off" denies success in a situation. "Chalk up" can also imply the action of making a mark that can be counted as a point, whereas "write off" can mean the act of canceling a debt or liability. As opposite words, they depict two separate outcomes: success or failure.