Hello Codeforces,

I wanted to share with you a web application I recently developed. The application filters out unsuccessful contests you have participated in on Codeforces and predicts your rating today based on only the optimal contests. Initially, my idea was to greedily select contests that have a positive delta based on the current rating, using the rating formula mentioned in this blog post. However, due to slow API calls, I was almost ready to give up on the project. Nevertheless, I decided to proceed for the sake of completeness.

To my surprise, when I completed the application, I found the results to be quite interesting. Additionally, I added a mode that computes the rating using a simple O(1) formula: $$$ delta = (performance - rating) / 4 $$$. I found that not only did this computation take less time, but the results were also convincing.

I thought it would be valuable to share this application with you, as it may provide insights and assistance to Codeforces users in predicting their ratings based on their contest performances.

Thank you for your time and consideration. If you have any further questions or would like to explore this application, please feel free to reach out to me.