CF ratings are unrelated to your IOI results. CF contests differ significantly from IOI contests.

❌ Wrong!

A higher CF rating, with a gap of at least 100, correlates with an 87% chance of achieving a better placement at IOI. In fact, the relationship between IOI placement and CF rating is strongly connected. The Pierson Correlation Coefficient for these two factors is -0.83.

Correlation between CF rating and IOI placement

❗ What is that outlier participant on the top-right? He is Jiyu Shen (PubabaOnO), with CF rating of 3000+, but it seems that he was unable to attend the contest 💔

Here are the statistics on CF ratings for each medal:

Additionally, I've discovered an interesting correlation: participants' ratings one year before IOI also correlate with their final ranks. By the way, some participants showed remarkable jumps in their ratings during that one-year period. Specifically, there were 4 participants with 1000+ growth in CF rating!

Correlation between CF rating a year before IOI and IOI placement

Based on this insight, I’ve trained a model that can predict your placement at IOI. If you’re curious about your predicted placement for IOI 2025, leave a comment! Note that as time passes, the model can determine your place more accurately. So you may comment again 6 months later to see the updated prediction.

Check out the similar blog for IOI 2019 here.