Walleye — Research & Methodology (v1)
Last updated: 2026-02-15
This page documents the variables we use for Walleye (v1), the open-access URLs behind each driver, verbatim quotes (with page pointers where available), and what is research-backed vs calibrated. We do not publish proprietary weights, caps, or equations.
How it works (overview)
Walleye (v1) is a freshwater Major-window rating: each Major solunar window (moon overhead / underfoot) gets a 1.0–5.0 score, and the day score is the duration-weighted average of the Major-window scores.
We combine moon position (overhead/underfoot), moon phase (gibbous higher, quarter lower), dawn/dusk overlap (civil twilight), low-light timing (dawn/dusk window from research), and cloud cover as a proxy for solar radiation. A seasonality multiplier is applied so spring/summer patterns from the literature are reflected. Research chooses the drivers; we calibrate their relative importance and how they map onto 1.0–5.0 so the scale is stable. For display, we use a percentile-based mapping so 1.0 and 5.0 are meaningfully rare; 1.0 means "worst predicted conditions relative to our benchmark population," not "you will catch nothing." Exact weights, caps, and percentile breakpoints are proprietary.
Variables (what’s research-backed vs calibrated)
Research-backed means the driver/pattern/mechanism is supported by open-access sources. Calibrated means we chose the exact thresholds/weights/caps to make a stable 1–5 score and to avoid dominance/double-counting.
Moon position (Majors only)
Research-backed: Walleye trip success is ~10–12% higher when the moon is overhead/underfoot.
Calibrated: mapping the research effect into a lift contribution; exact value is proprietary.
Source (open access): Shaw et al. 2021 — PLOS ONE
“Anglers were observed to be about 10–12% more likely to be successful when the moon was overhead or underfoot…”
(PDF p.13)
Moon phase
Research-backed: gibbous phases highest; quarter phases lowest (ordering used).
Calibrated: exact curve shape and relative weight are proprietary.
Source (open access): Shaw et al. 2021 — PDF (printable)
“The odds of a successful trip were highest during the gibbous phases… and lowest during the quarter phases…”
(PDF p.13)
Low-light / crepuscular timing (L_time)
Research-backed: dusk and dawn are better than day; lower light improves success.
Calibrated: the maximum lift size and the exact dawn/dusk window used for scoring (see verification section for the window definition source).
Source (open access): Shaw et al. 2021 — PDF (printable)
“…The predicted odds of a successful trip was highest at dusk … followed by dawn … and then day …”
(PDF p.8)
“…increased as light conditions decreased (i.e., decreasing solar radiation and the diel periods of dawn or dusk relative to daytime).”
(PDF p.25)
Cloud cover (proxy for solar radiation) (part of L_time)
Research-backed: mean daily solar radiation negatively affects trip success; authors treat solar radiation as influenced by cloud cover.
Calibrated: mapping cloud cover % to a small lift (we keep it conservative).
Implementation note: PrimeBite uses Open‑Meteo cloud cover (%) as a proxy for light intensity, using a daytime average (≈9am–3pm local) when available.
Source (open access): Shaw et al. 2021 — PDF (printable)
“Mean daily solar radiation had a negative effect on walleye trip success… The observed percent of successful trips tended to increase with decreasing solar intensity …”
(PDF p.11)
“Solar radiation is influenced by solar altitude as well as cloud cover… Thus, mean daily solar radiation was assumed to represent cloud cover as well as seasonal or diel differences in solar intensity…”
(PDF p.5)
Dawn/dusk overlap with bite windows (L_overlap)
Research-backed: low-light periods improve success (Shaw 2021), so overlap with dawn/dusk is meaningful.
Calibrated: how overlap maps into points; magnitude and ceiling are proprietary.
Verification source: civil twilight definition (NOAA/NWS) is used so “dawn/dusk overlap” is a standard astronomical window.
Seasonality multiplier (seasonMult)
Research-backed: Walleye vulnerability/effort/catch commonly peak in spring and shift through the year in open-access regional sources.
Calibrated: monthly multipliers and a global cap keep seasonality meaningful but not dominant; exact values are proprietary.
Sources (open PDFs):
Weather (wind/precip/pressure)
Research-backed (decision to exclude): Shaw 2021 highlights wind direction (not wind speed) as highly weighted; precip/pressure were not highly weighted.
Calibrated/product choice: Walleye v1 does not apply wind/precip/pressure adjustments globally until effect sizes and generality are better supported.
Key definitions & verification sources
Some items are not “Walleye biology claims” — they are definitions needed for correct implementation.
Moon phase vs illuminated fraction
Why it matters: quarter phases can have similar illumination but different phase position; the Walleye phase model is based on phase position.
Source (open access): SunCalc docs (phase definition)
“Moon phase value should be interpreted like this: … 0 | New Moon … 0.25 | First Quarter … 0.5 | Full Moon … 0.75 | Last Quarter …”
Dawn/dusk window definition (±30 minutes)
Used for: the low-light window used by Walleye v1.
Source (open access): Vasquez 2024 — UWSP thesis
“Observations 30 mins before and after sunrise were classified as dawn and observations 30 mins before and after sunset were classified as dusk.”
(printed p.30)
Civil twilight definition (sun altitude −6°)
Used for: computing overlap_fraction for the overlap lift.
Source (open access): NWS/NOAA — Twilight definitions
“Morning civil twilight begins when the geometric center of the sun is 6 degrees below the horizon, and ends at sunrise. Evening civil twilight begins at sunset, and ends when the geometric center of the sun is 6 degrees below the horizon.”