How the 0 to 100 score works
The score on every spot card is a 0 to 100 number answering one question: if I drove there right now, how likely am I to catch fish? Higher is better; scores below 30 signal conditions to avoid.
The primary number on a spot page represents the composite score, calculated as the highest species rating for that location. The species pills underneath provide the detailed breakdown. A spot can score 70 for crappie and 25 for trout on the same day; the resulting composite displays as 70.
Rating categories
- excellent (85+): conditions strongly favor the angler
- good (70 to 84): productive water with reliable catch potential
- fair (50 to 69): fishable water where presentation matters
- poor (30 to 49): adverse conditions resulting in cautious feeding
- skip (0 to 29): tough conditions better spent off the water
What drives the number
Scores recalculate hourly based on eight environmental factors:
1. Water temperature: matched against biological comfort ranges for each species. Cold water in winter slows digestion; warm water in summer stresses trout.
2. Barometric pressure trend: 12-hour slope. Steady or falling pressure ahead of a weather front encourages feeding; sharp post-front spikes shut fish down.
3. Streamflow and lake elevation: discharge and gauge height from USGS stream gauges compared against seasonal medians. Blown-out rivers incur heavy penalties.
4. Hydropower dam generation: hourly generation releases from TVA and USACE dams. Turbine operations create dangerous wading conditions and wash out drifts on tailwaters.
5. Solunar timing: major and minor feeding periods derived from lunar overhead and underfoot positions, alongside civil twilight windows.
6. Recent precipitation: 24-hour and 72-hour rainfall totals from NOAA NWS and Open-Meteo, separating fresh runoff rises from heavy mud and sediment.
7. Cloud cover and wind: surface chop and light levels. Bright direct sunlight in clear water spooks fish, while cloud cover and light chop bring them out of cover.
8. Stocking and advisories: recent TWRA stocking events within 14 days boost targeted species. Active TDEC harmful algae bloom advisories apply immediate penalties.
Known limitations
The engine aggregates public sensor feeds and statistical models. It does not observe:
- Hyper-local events: unmonitored agricultural runoff, localized chemical spills, or high bank fishing pressure that bypass upstream gauges.
- Micro-structure: whether fish hold on a secondary ledge versus a main-lake hump requires angler exploration.
- Unannounced stocking: unscheduled hatchery truck deliveries not yet posted to state feeds.
How to use the score
Start on the Today overview to scan locations across Tennessee ranked by condition. The best-bites header flags the top-scoring species statewide at the current hour. Each spot page details factor breakdowns and gear recommendations suited to current water conditions.
Calibration and back-testing
Catch reports submitted through /catches store condition snapshots at the time of catch. The engine correlates this history with TWRA stocking logs, fly shop fishing reports, and regional reference models to refine scoring accuracy.
Transparent scoring
Spot pages display each individual score component rather than an unexplained black-box rating. When conditions on the water differ from predictions, reviewing the breakdown shows exactly which factors shaped the score.