Accuracy
How accurate is the Chimpers model?
Every estimate is benchmarked against real sales the model never trained on (a seeded 80/20 hold-out).
Median accuracy
88.2%
Mean accuracy
85.4%
Within ±5%
24%
Within ±10%
41%
Within ±20%
72%
Bias
+4.5%
Weekly median accuracy
Hold-out accuracy by week
Error distribution
Signed % error on recent sales (0 = perfect)
Recent sales vs model
The 60 most recent sales, each valued as of its sale date
| Item | Date | Sale | Model | Error | Accuracy |
|---|---|---|---|---|---|
| #4656 | Jun 14, 2026 | 0.953Ξ | 0.720Ξ | +32.3% | 67.7% |
| #4656 | Jun 14, 2026 | 0.680Ξ | 0.720Ξ | -5.6% | 94.4% |
| #4064 | Jun 13, 2026 | 0.637Ξ | 0.625Ξ | +2.0% | 98.1% |
| #672 | Jun 12, 2026 | 0.840Ξ | 0.820Ξ | +2.5% | 97.6% |
| #4426 | Jun 12, 2026 | 0.695Ξ | 0.650Ξ | +6.8% | 93.2% |
| #1375 | Jun 12, 2026 | 0.695Ξ | 0.674Ξ | +3.1% | 96.9% |
| #4655 | Jun 11, 2026 | 1.190Ξ | 0.975Ξ | +22.0% | 78.0% |
| #2331 | Jun 10, 2026 | 0.630Ξ | 0.640Ξ | -1.6% | 98.4% |
| #4261 | Jun 10, 2026 | 0.858Ξ | 0.664Ξ | +29.3% | 70.7% |
| #4426 | Jun 10, 2026 | 0.620Ξ | 0.651Ξ | -4.8% | 95.3% |
| #3264 | Jun 9, 2026 | 0.770Ξ | 0.689Ξ | +11.8% | 88.2% |
| #264 | Jun 9, 2026 | 0.900Ξ | 0.811Ξ | +11.0% | 89.0% |
| #1375 | Jun 8, 2026 | 0.574Ξ | 0.675Ξ | -14.9% | 85.1% |
| #4448 | Jun 8, 2026 | 0.655Ξ | 0.614Ξ | +6.7% | 93.3% |
| #4265 | Jun 8, 2026 | 0.655Ξ | 0.684Ξ | -4.3% | 95.8% |
| #4252 | Jun 8, 2026 | 0.655Ξ | 0.603Ξ | +8.6% | 91.4% |
| #3624 | Jun 7, 2026 | 0.659Ξ | 0.672Ξ | -2.0% | 98.0% |
| #4349 | Jun 7, 2026 | 0.690Ξ | 0.678Ξ | +1.8% | 98.2% |
| #186 | Jun 7, 2026 | 0.653Ξ | 0.675Ξ | -3.3% | 96.7% |
| #4261 | Jun 6, 2026 | 0.612Ξ | 0.665Ξ | -8.0% | 92.0% |
| #817 | Jun 6, 2026 | 0.580Ξ | 0.620Ξ | -6.5% | 93.5% |
| #4969 | Jun 6, 2026 | 0.634Ξ | 0.648Ξ | -2.1% | 97.9% |
| #4969 | Jun 6, 2026 | 0.573Ξ | 0.648Ξ | -11.5% | 88.5% |
| #931 | Jun 6, 2026 | 0.650Ξ | 0.619Ξ | +5.0% | 95.0% |
| #4252 | Jun 5, 2026 | 0.555Ξ | 0.604Ξ | -8.1% | 92.0% |
| #931 | Jun 5, 2026 | 0.560Ξ | 0.619Ξ | -9.5% | 90.5% |
| #4261 | Jun 5, 2026 | 0.563Ξ | 0.666Ξ | -15.4% | 84.6% |
| #4448 | Jun 4, 2026 | 0.575Ξ | 0.614Ξ | -6.4% | 93.6% |
| #797 | Jun 4, 2026 | 0.690Ξ | 0.643Ξ | +7.3% | 92.7% |
| #5315 | Jun 2, 2026 | 0.750Ξ | 0.715Ξ | +4.8% | 95.2% |
| #797 | Jun 2, 2026 | 0.582Ξ | 0.646Ξ | -9.9% | 90.1% |
| #3920 | Jun 1, 2026 | 0.698Ξ | 0.683Ξ | +2.3% | 97.7% |
| #4681 | Jun 1, 2026 | 0.750Ξ | 0.722Ξ | +3.9% | 96.2% |
| #3624 | Jun 1, 2026 | 0.622Ξ | 0.678Ξ | -8.2% | 91.8% |
| #186 | Jun 1, 2026 | 0.650Ξ | 0.681Ξ | -4.5% | 95.5% |
| #3920 | Jun 1, 2026 | 0.644Ξ | 0.684Ξ | -5.8% | 94.2% |
| #2645 | May 31, 2026 | 0.745Ξ | 0.653Ξ | +14.0% | 86.0% |
| #580 | May 30, 2026 | 0.798Ξ | 0.765Ξ | +4.3% | 95.8% |
| #2132 | May 29, 2026 | 0.640Ξ | 0.663Ξ | -3.5% | 96.5% |
| #1357 | May 29, 2026 | 0.690Ξ | 0.704Ξ | -2.0% | 98.0% |
Method details on the methodology page.