How TagMath Calculates Draw Odds
Every number has a source. Every recommendation is traceable.
Data Sources
CPW Draw Recap Reports (2020–2025)
Official post-draw reports published by Colorado Parks & Wildlife. Contains pre-draw applications by hunt code and preference point level, plus post-draw results (tags issued, cutoff points, total drawn).
View source at CPW →CPW Harvest Reports (2024)
Annual harvest survey estimates — success rates, total harvest, hunter-days by Game Management Unit. Survey-based for deer, elk, and pronghorn; mandatory reporting for moose, sheep, and goat.
2026 Big Game & Sheep/Goat Brochures
Current-year hunt code catalog with quotas, season dates, and unit descriptions. Used to identify new/removed hunt codes for 2026.
CPW GIS — GMU Boundaries
186 Game Management Unit polygons from CPW's ArcGIS REST API (HuntingAtlas Base Map, Layer 81). Simplified for web rendering.
Odds Calculation Method
Preference Point Species (Elk, Deer, Antelope, Bear)
Colorado uses a preference point system for these species. Applicants with the most points draw first. TagMath analyzes 6 years of draw data to calculate:
- Historical cutoff points — the minimum points needed to draw each year (2020–2025)
- Point creep — how fast the cutoff is rising, using robust statistical regression that handles outlier years better than simple averages
- Projected 2026 cutoff — where the cutoff is likely to land based on the trend
- Draw probability at your point level — using weighted historical rates with recent years weighted more heavily than older data
Weighted Draw Species (Moose, Rocky Mountain Bighorn Sheep, Mountain Goat)
These three species use a preference-weighted lottery — more points = more entries in the draw, but no guaranteed cutoff. Per the 2026 Big Game Brochure, hunters accumulate up to three points; at the cap, your application number is divided by your weight (points + 1) before sorting. TagMath uses a weighted heuristic that models the lottery probability based on historical draw rates at each point level. Results are labeled with method: weighted-heuristic for transparency.
Random Draw (Desert Bighorn Sheep)
Desert bighorn sheep is the only Colorado big-game species that uses a pure random draw. Per the 2026 CPW Sheep & Goat Brochure (page 12): “Preference points do not apply to desert bighorn sheep. The draw for desert bighorn sheep is random.” Your probability is simply quota ÷ applicants regardless of how many points you have. Note: you cannot apply for both Rocky Mountain bighorn and desert bighorn in the same year. Results are labeled with method: random-draw.
Confidence Levels
Each odds estimate includes a confidence rating based on data quantity and year-to-year volatility:
- High — 5+ years of data and the year-to-year draw rate is steady (std dev under 10 percentage points)
- Medium — 3-4 years of data, OR 5+ years but the rate has been volatile (10-25pp std dev)
- Low — limited data, new hunt code, methodology change, or year-to-year rate swings exceed 25pp
When a hunt's historical draw rate has swung by more than 25 percentage points across years, we render a Volatile odds badge on the hunt page. The headline number is still the best point estimate, but treat it as a band rather than a forecast.
Quota Changes
When CPW raises or cuts a unit's quota by 30% or more year-over-year, the supply/demand regime has changed. Blending pre-change years into the time-weighted draw rate would mislead the model. We detect these changes automatically and drop pre-change years from the rate average; affected hunts show a Quota changed disclosure with the year and prior quota.
First-Choice vs. Other-Choice Draws
CPW's “X of Y at N pp” final rate string counts any hunter who drew this code at N preference points — including those who applied with this code as a 2nd, 3rd, or 4th choice after their first choice failed. It does not isolate 1st-choice draws.
Practical implication: if your preference points are several below a unit's projected cutoff, the historical “100% drew at 5 pp” rate is often leftover / other-choice activity, not a 1st-choice opportunity. Hunt detail pages now label these rows accordingly. The headline draw probability on /api/odds clamps to ≤ 2% when your point level is more than three points below the projected cutoff — exactly to avoid misreading these rows as guidance.
What We Don't Do
- ✕No AI hallucination. Zero LLM calls in the data pipeline. Every number comes from deterministic parsing of official state wildlife agency publications.
- ✕No made-up odds. If we don't have enough data for a hunt code, we say so — we never fill gaps with guesses.
- ✕No hidden methodology. This page explains exactly how every number is calculated. The math is verifiable.
- ✕No guarantees. Draw odds are probabilistic estimates based on historical data. CPW can change quotas, rules, and point structures at any time.
Data Coverage
15,106
Hunt Codes
8
Species
6
Years
186
GMUs Mapped
Why Our Numbers May Differ From Other Tools
If you compare TagMath odds to other draw calculators (like onX), you may see different numbers for the same hunt code. This is expected and not a bug.
Key differences:
- Weighting method: TagMath weights recent years more heavily than older data (a 2025 draw is more predictive than 2020). Other tools may use simple averages or different weighting schemes.
- Point creep model: We use Theil-Sen regression (robust to outliers) rather than ordinary least squares. This handles years with unusual quota changes more gracefully.
- Scope: We analyze all applicants at every point level, not just first-choice or top-point applicants.
Both approaches are defensible. We chose methods that prioritize accuracy over simplicity, and we show our work so you can verify.
Under the Hood
Data pipeline: Pure deterministic parsing — no AI/LLM in the data pipeline. Every number is directly extracted from official state wildlife agency publications.
Harvest data: CPW Big Game Harvest Survey (stratified random sample, ~50% response rate)
Map: Open-source mapping with official state wildlife agency ArcGIS boundary data
Updates: New draw data integrated within 30 days of CPW publication each year
Frequently Asked Questions
What are the Colorado elk draw odds for 2026?
Draw odds vary by Game Management Unit, preference points, season, and residency status. TagMath calculates your exact draw probability across 15,000+ hunt codes using 6 years of official CPW Draw Recap data (2020–2025). For example, popular bull elk units like GMU 61 require 5+ preference points for rifle seasons, while many cow elk tags are available with 0 points.
How many preference points do I need for Colorado elk?
It depends on the unit and season. Premium bull elk units (like GMU 201 or GMU 2) can require 15–20+ points, while many either-sex and cow tags draw with 0–3 points. Use the TagMath interactive map to see point cutoff trends for every unit.
When is the Colorado big game application deadline?
The Colorado primary draw application deadline is April 7, 2026 at 8:00 PM MDT. Applications must be submitted online at cpw.state.co.us. TagMath helps you research units and build your strategy before the deadline.
How does TagMath calculate draw odds?
We use official CPW Draw Recap Reports (2020–2025) with zero AI/LLM in the data pipeline. For preference-point species (elk, deer, antelope, bear), we use Theil-Sen regression for point creep and exponential weighting that prioritizes recent years. For weighted-draw species (moose, sheep, goat), we use a weighted heuristic model. Every number links to its source.
How is TagMath different from GoHunt, Huntin' Fool, or onX?
TagMath starts at $14.99 (Season Pass) or $49/year (Pro) — all species, all seasons, all data included. GoHunt Insider is $150/year, Huntin' Fool is $150/year (often with a waitlist), and onX Elite is $100/year. We also publish our full methodology and cite every data source, so you can verify our numbers yourself.
Does TagMath use AI to generate odds?
No. The data pipeline is 100% deterministic — every number is directly parsed from official CPW publications. AI is only used in the premium strategy layer for personalized recommendations. The underlying odds calculations use standard statistical methods (Theil-Sen regression, exponential weighting) with no LLM involvement.
What species does TagMath cover?
TagMath covers all 8 Colorado big game species: elk, mule deer, pronghorn (antelope), black bear, moose, Rocky Mountain bighorn sheep, desert bighorn sheep, and mountain goat. That's 15,000+ hunt codes across 186 Game Management Units.
Still have questions? See our FAQ →
“Stop guessing. Start planning.”™