Reading IVs from the appraisal screen

The classical IV calculator pipeline (CP + HP + dust) is a constraint solver — it usually returns 2-5 candidate combos that all match the inputs. Disambiguating requires either powering up the mons (expensive) or waiting for a level milestone (slow).

The appraisal screen, since 2019, shows three horizontal bars: one for Attack, one for Defense, one for HP. Each bar fills proportionally to that single IV value (0-15). Read correctly, the bars give you exact IVs in one screenshot — no math required.

Hundo Hunter's broadcast extension OCRs the appraisal screen during a Live capture session and parses the fill ratio of each bar directly from pixel data, so the result is deterministic.

segment_count = 3              // each bar is split into 3 wedges
iv_per_segment = 5             // 5 IV points per filled wedge
iv_max_per_stat = 15           // 3 × 5

fill_ratio = filled_pixels / total_bar_pixels
iv = round(fill_ratio × 15)

if bar_color == RED_HEX: iv = 15   // confirmed hundo on this stat

The bar reading isn't quite enough on its own — these modifiers change what the bar means in practice:

• ▸Lucky — does not change IVs or bar fill, only halves stardust costs. No appraisal-side adjustment needed.
• ▸Best Buddy — boosts the effective level by +1 in combat but does not change the underlying IVs or appraisal bar fill. Bars still read the catch IVs.
• ▸Weather boost — captured mons spawn at L25 with min-10 IVs. Bars still read 0-15 absolute values; the 10-floor only affects the search space when no appraisal is available.
• ▸Shadow → Purified — Purify adds +2 to every IV (capped at 15). We re-read the bars post-purification and surface the pre-purify spread in the dex entry.
• ▸Trade — re-rolls IVs in the trade-floor range (1-15, or 5-15 / 10-15 / 12-15 for friendship tiers). Bars must be re-read after the trade.

Niantic's server-side IVs are integers 0-15 and are never exposed to clients in raw form. Every third-party IV tool — including ours — reverse-engineers them from client-visible signals.

The bar method we use is the most reliable client-visible signal available, with no ambiguity once the OCR fill ratio is read correctly. It outperforms CP back-calc by eliminating the 2-5 candidate combos at appraisal time.