Does the model actually work?
Everything else here works out what you should provide. This page checks whether the model that produced it has ever been right. Give it a period that has already finished — the PDs you used at the start, and what actually happened by the end.
Failed on calibration. The allowance this model produces is understated.
This example is meant to fail. The book is 1,200 synthetic borrowers with one grade deliberately wrong: BB was priced at 2.00% and defaulted at 6.00%.
Notice what still passes. The ranking is sound, and the portfolio total — 3.75% observed against 2.75% predicted — reads as acceptable. That is the whole point: a portfolio-level test nets an understated grade against a conservative one and reports nothing wrong, so calibration is tested grade by grade. Load your own file above to replace this.
Your data
One row per borrower. Two columns are essential: the PD you predicted, and whether it defaulted.
This is an example book of 1,200 synthetic borrowers, not your data. It is here so the page shows what it does before you have fetched anything. Replace it when you are ready.
Read 1,200 rows and 5 columns.
Which column is which
Corrected automatically where the heading is recognisable. Change anything that is wrong.
Every value sits in the decimal range. Read the wrong way round, a model would look a hundred times more conservative than it is and pass every test on this page.
Can it tell good from bad?
Whether the model RANKS risk. A model that cannot rank is not repairable by recalibration.
Gini 0.568, confidence interval from 0.408 to 0.729, on 45 defaults. The model separates defaulting from performing obligors.
Are the levels right?
Whether the PDs match what happened — tested per grade, because a total can net an understated grade against an overstated one.
The portfolio total is acceptable, but 1 grade (BB) understate default risk at the 1% level. A total that nets out an understated grade against an overstated one is not a calibrated model.
| Grade | Borrowers | Defaults | Predicted | Observed | Predicted vs observed | Jeffreys p | |
|---|---|---|---|---|---|---|---|
| A | 300 | 1 | 0.30% | 0.33% | 0.3847 | Passed | |
| BBB | 350 | 3 | 0.90% | 0.86% | 0.4931 | Passed | |
| BB | 300 | 18 | 2.00% | 6.00% | <0.0001 | Failed | |
| B | 180 | 11 | 5.51% | 6.11% | 0.3453 | Passed | |
| CCC | 70 | 12 | 18.08% | 17.14% | 0.5680 | Passed |
Correlation assumption
Used for the bound that allows for defaults arriving together rather than independently.