Notebook — Hockey Alchemy
Methodology breakdowns, model validations, and analytical deep-dives from the Hockey Alchemy team. New posts every few weeks.
Inside the NHL EDGE Goal Visualizer: How We Scrape, Clean and Use Tracking Data
2026-09-30
The NHL publishes about fourteen seconds of player tracking for every goal, ten frames a second. We hold 26,237 of them. How we fetch it, the four bugs we shipped handling it - none of which ever errored - what it is good for, and the one thing it can never do.
Our 2026-27 NHL Projection, and Exactly How Much to Discount It
2026-09-29
Carolina 111.6 points, Vancouver 79.1 - and luck alone gives the average team an 80% range 21.8 points wide, two-thirds of the league's entire spread. Our measured error says the honest range is closer to 32. The projection beats the honest baseline, and here is exactly how much of the table you should refuse to read as a ranking.
Talent vs Production: Why the Box Score Misleads
2026-08-16
Two wingers score 20 goals; only one of them will do it again. The gap between what a player produced and the process underneath it is the most useful idea in hockey analytics - and it is the split our expected-goals and finishing models are built to make.
How Good Is Our WAR Model? We Ran Four Tests and Lost Two
2026-08-16
We tested our WAR model against HockeyStats and Evolving Hockey on the four questions an honest player-value model has to answer, matched to each benchmark's published protocol. Summed to a team it loses both tests - it forecasts next season worse than simply reusing last season's standings. Measured per player it wins both, repeating at 0.77 against 0.62 and 0.46.
The Model That Earns Its Keep
2026-08-16
Is our projection actually better than a simple average? We ran the honest test - forecasting one player's WAR next season, walk-forward across thirteen seasons - and beat the baseline that is supposed to be unbeatable. Then we ran it on goalies, where we lose.
Which Hockey Stats Are Skill, and Which Are Luck?
2026-08-16
Line up every player's value in a category this season against next season and you get a brutal skill-vs-luck test. Staying out of the penalty box repeats more than four times better than finishing - and it changes how you should read a stat line.
What's Actually Inside a GAR Number
2026-08-01
GAR compresses a season into one figure - so the parts underneath had better add up. What our GAR is actually made of, why it is anchored on counting stats rather than built purely from RAPM (measured: pure RAPM drops standings R-squared from 0.75 to 0.51), and the bug that left our own component breakdown failing to sum to the number above it.
Why Public Hockey Analytics Is Imperfect
2026-07-20
An honest accounting of where public hockey analytics hits a wall — the data ceiling (the feed records no passes, tracking drifts, private camera models see more) and the bigger problem now: a discourse that shares cards without meaning, rewards certainty over nuance, and stopped teaching. With the Zach Hyman case as the tell.
Distance and Angle Aren't Enough: Why Our xG Model Splits the Ice Into Zones
2026-07-20
A pure distance-and-angle expected-goals model looks reasonable — and quietly misprices the whole ice. We map exactly where it goes wrong, then show how zone, rush, and prior-event features lift out-of-sample AUC from 0.70 to 0.84.
How Our Expected Goals (xG) Model Works
2026-07-20
A transparent look inside Hockey Alchemy's xG model: situation-specific XGBoost models, 53 features, 16 seasons and 1.6M shots — and how it stacks up against MoneyPuck on a matched-shot test.
The 2026-27 NHL Schedule, by Team: Who the 84-Game Grid Favors
2026-07-19
The NHL's first 84-game season since 1993-94, by team impact: the rest edges that actually tilt the standings, full strength-of-schedule for all 32 teams, how the identical divisional structure shapes every slate, plus opening night and five nights outdoors.
What to Expect With Jim Hiller
2026-07-19
Toronto tried the Cup-pedigree hire and Auston Matthews cratered. What Jim Hiller's actual Kings numbers — and our metrics — say to expect from the Leafs' next coach.
Introducing the Hockey Alchemy Chrome Extension
2026-07-02
GAR, tier, and contract value for any NHL player — in a popup, a side panel, or highlighted right on the pages you already read. Free, no account, no tracking.
Jet Greaves Is the NHL’s Most Underrated Goalie
2026-06-29
Columbus' Jet Greaves was a top-7 NHL goalie in 2025-26 by shot-quality-adjusted GSAx — all on an $812,500 cap hit. The case the box score hides.
How We Calculate NHL Power Rankings: The Elo System Behind Hockey Alchemy
2026-05-23
A transparent look at the Elo rating system that powers our NHL power rankings, game predictions, and Stanley Cup odds. K=12, home ice = 50 points, 30% regression to the mean — and three different ways we account for margin of victory.