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Hard rules, never broken silently

A hard rule is one the allocator keeps on every slot it gives out. Any rule it cannot keep is named with the reason: a lock that breaks one is left out and listed, and a hand move that breaks one is flagged on the calendar.

What it balances

Within the hard rules, the allocator scores each allocation and keeps the best one it finds. A team's shortfall is measured as a share of its own target and squared: one team missing its whole target costs 1050 points, one missing half costs 275, and two teams each missing a quarter cost 150 between them, so shortages are spread in proportion to targets. With spare ice left unused, each hour over a target costs 40 points. Prime time share and early and late slots are evened out within each division, a practice away from a team's preferred arena costs 6, and in a rebalance each booking a team loses costs 30, so a rebalance moves as little as it can.

The search is deterministic: the same season and seed always give the same allocation. It runs between 60,000 and 400,000 steps in a background worker, depending on the size of the season, then fills any slot a team below its target can still take.

Why a team is short

For every team below its target, the allocator counts the slots it did not get, by the first reason that stops it:

Straight after an allocation it never lists a free slot the team could take: any such slot is given to the team before the reasons are worked out. After hand moves, a free slot a team could take is listed as such.

Last reviewed 27 September 2026. Icesheet is not affiliated with any hockey association, governing body, league, arena, municipality or ice scheduling software company.