Data Limitations

What the records here do not cover, and why

NHL

Every game since 1917-18 comes from the NHL's own stats. Standings rank by points: two for a win, one for a tie, and from 1999-2000 one for a loss in overtime or a shootout.
Head coaches come from Wikipedia's lists of each club's coaches, by season, not by game. A coach who had every game of his seasons has his record counted from the games; where a coach changed in mid-season, both records are the list's, and a few the lists have wrong are corrected by hand. Records run through last season.
Some lists give ties and overtime losses as one number. Those coaches show them all as ties.
A coach is marked as an interim only where a club's list marks one, which today is Philadelphia's and Toronto's.

The season being played is shown from ESPN's public scoreboard, which can briefly differ from the league's own record of a game.
No box scores or player statistics are loaded. Records that need them — no-hitters, cycles, earned run averages, a player's game — are left out rather than shown empty, and there are no player pages.
Each league's day-by-day and week-by-week scores come from ESPN's scoreboard, which reaches back years rather than to each league's first season. "Every season, from the record" under that list has the whole history.