Accuracy
How accurate is the Chimpers model?
Every score comes from the newest chronological hold-out; the target sale is excluded from training, comparables, and its causal floor proxy.
Median accuracy (100−APE)
86.9%
Mean accuracy (100−APE)
83.9%
Within ±5%
18%
Within ±10%
39%
Within ±20%
72%
Bias
-6.8%
Accuracy by market tier
Floor, middle-market, and grail sales are scored separately so aggregate accuracy cannot hide a weak segment
| Tier | Sales | Median accuracy | Within ±10% | Bias |
|---|---|---|---|---|
| floor | 212 | 87.4% | 40% | -6.5% |
| middle | 3 | 82.7% | 0% | +23.0% |
| grail | 5 | 75.8% | 0% | -34.7% |
Weekly median accuracy
Chronological hold-out accuracy by sale week
Error distribution
Signed hold-out error; positive means over-predicted
Scored hold-out sales
60 out-of-sample predictions frozen at evaluation time
| Item | Tier / evidence | Date | Sale | Model | Error | Accuracy |
|---|---|---|---|---|---|---|
| #3504 | floor · high | Nov 5, 2026 | 0.388Ξ | 0.348Ξ | -10.3% | 89.7% |
| #674 | floor · high | Nov 1, 2026 | 0.380Ξ | 0.350Ξ | -7.9% | 92.1% |
| #3005 | floor · high | Nov 1, 2026 | 0.399Ξ | 0.348Ξ | -12.8% | 87.2% |
| #5208 | floor · high | Oct 31, 2026 | 0.324Ξ | 0.369Ξ | +13.9% | 86.1% |
| #919 | floor · high | Oct 31, 2026 | 0.376Ξ | 0.423Ξ | +12.6% | 87.4% |
| #4694 | floor · high | Oct 30, 2026 | 0.550Ξ | 0.379Ξ | -31.1% | 68.9% |
| #3003 | floor · high | Oct 30, 2026 | 0.398Ξ | 0.319Ξ | -19.8% | 80.2% |
| #3005 | floor · high | Oct 30, 2026 | 0.348Ξ | 0.379Ξ | +8.9% | 91.1% |
| #3002 | floor · high | Oct 30, 2026 | 0.325Ξ | 0.358Ξ | +10.2% | 89.9% |
| #3007 | floor · high | Oct 30, 2026 | 0.313Ξ | 0.343Ξ | +9.6% | 90.4% |
| #3003 | floor · high | Oct 30, 2026 | 0.314Ξ | 0.363Ξ | +15.6% | 84.4% |
| #3725 | floor · high | Oct 30, 2026 | 0.450Ξ | 0.347Ξ | -22.9% | 77.1% |
| #1014 | floor · high | Oct 28, 2026 | 0.336Ξ | 0.410Ξ | +22.0% | 78.0% |
| #4729 | floor · high | Oct 28, 2026 | 0.336Ξ | 0.364Ξ | +8.3% | 91.7% |
| #1440 | floor · high | Oct 26, 2026 | 0.347Ξ | 0.369Ξ | +6.3% | 93.7% |
| #3608 | floor · high | Oct 25, 2026 | 0.350Ξ | 0.357Ξ | +2.0% | 98.0% |
| #3590 | floor · high | Oct 24, 2026 | 0.362Ξ | 0.329Ξ | -9.1% | 90.9% |
| #3495 | floor · high | Oct 24, 2026 | 0.990Ξ | 0.463Ξ | -53.2% | 46.8% |
| #1409 | floor · high | Oct 23, 2026 | 0.450Ξ | 0.366Ξ | -18.7% | 81.3% |
| #5285 | floor · high | Oct 23, 2026 | 0.500Ξ | 0.498Ξ | -0.4% | 99.6% |
| #3496 | grail · medium | Oct 23, 2026 | 1.990Ξ | 0.405Ξ | -79.7% | 20.4% |
| #919 | floor · high | Oct 21, 2026 | 0.448Ξ | 0.351Ξ | -21.7% | 78.4% |
| #4531 | floor · high | Oct 21, 2026 | 0.449Ξ | 0.356Ξ | -20.7% | 79.3% |
| #2558 | floor · high | Oct 20, 2026 | 0.500Ξ | 0.343Ξ | -31.4% | 68.6% |
| #2881 | grail · high | Oct 20, 2026 | 0.551Ξ | 0.379Ξ | -31.2% | 68.8% |
| #639 | floor · high | Oct 16, 2026 | 0.386Ξ | 0.338Ξ | -12.4% | 87.6% |
| #3156 | floor · high | Oct 14, 2026 | 0.399Ξ | 0.319Ξ | -20.1% | 80.0% |
| #719 | floor · high | Oct 14, 2026 | 0.690Ξ | 0.338Ξ | -51.0% | 49.0% |
| #673 | floor · high | Oct 14, 2026 | 0.603Ξ | 0.358Ξ | -40.6% | 59.4% |
| #1506 | floor · high | Oct 14, 2026 | 0.440Ξ | 0.382Ξ | -13.2% | 86.8% |
| #50 | floor · high | Oct 14, 2026 | 0.460Ξ | 0.342Ξ | -25.7% | 74.4% |
| #3603 | floor · high | Oct 14, 2026 | 0.470Ξ | 0.336Ξ | -28.5% | 71.5% |
| #2767 | floor · high | Oct 14, 2026 | 0.496Ξ | 0.347Ξ | -30.0% | 70.0% |
| #4421 | floor · high | Oct 14, 2026 | 0.496Ξ | 0.349Ξ | -29.6% | 70.4% |
| #1743 | floor · high | Oct 14, 2026 | 0.499Ξ | 0.386Ξ | -22.7% | 77.4% |
| #1266 | floor · high | Oct 14, 2026 | 0.496Ξ | 0.365Ξ | -26.4% | 73.6% |
| #3267 | floor · high | Oct 14, 2026 | 0.448Ξ | 0.359Ξ | -19.9% | 80.1% |
| #3954 | floor · high | Oct 14, 2026 | 0.496Ξ | 0.318Ξ | -35.9% | 64.1% |
| #4295 | floor · high | Oct 14, 2026 | 0.499Ξ | 0.318Ξ | -36.3% | 63.7% |
| #5406 | floor · high | Oct 14, 2026 | 0.369Ξ | 0.327Ξ | -11.4% | 88.6% |
Model chimpers-1793842199-2026-08-03.2 · evaluated through 11/5/2026. Method details on the methodology page.