How Box Out learns your league
Written from what the software does, on September 30, 2026. Where a sentence says what the software does not do, that is a fact about the code as it stands, not a promise; a change to any of it changes this page.
Box Out measures your league on your league's own seasons, not on someone else's. The figures on the front page were measured on eight seasons of one real league. When your league connects, the same measurements are made again on your league's history alone, and every figure a page shows says which one it is using and on how much.
What happens after you connect
Connecting starts a run of eight steps, one after another. The account page (League connection, "Your league's numbers") shows the step it is on in the words in bold.
- reading your seasons from ESPN (minutes a season): every season ESPN has kept for your league, newest first.
- storing the NBA schedules behind them (seconds a season): which nights each NBA team played, season by season.
- measuring what a pickup is worth (seconds): what an ordinary waiver pickup has returned in your league, from the adds its teams really made.
- measuring what an open roster place is worth (seconds): what a place left open and streamed has returned, week by week.
- backtesting the bars (the long one) (about forty minutes a season): your league's mornings replayed to set the three bars a move is labelled against: this week's move, a move that costs FAAB, and a free add.
- replaying your trades (a minute or two): how often the trade number picked the side that did better over the thirty days after each deal.
- comparing you with the other leagues measured (under a second): your league's numbers join the pool of leagues with your settings.
- writing to you (under a second): a summary of every number, where it came from and what it rests on.
The times are from a run over nine seasons of one league; the first two depend on ESPN. What a pickup and an open place are worth arrive within minutes. The bars, the trade record and the summary wait for the long step: five or six hours for nine seasons. It runs behind everything else, so your pages are never waiting on it, and a season at a time, so a run that stops picks up where it stopped.
Where each number comes from, in order
- The league owner's own setting. The three bars are a choice about how many moves a manager wants to make, so the league's owner may set each one, with a line of why. A new measurement never overwrites it.
- Measured on your league, when there is enough of your history for the number to mean something (the next section).
- Pooled from leagues like yours: at least three measured leagues, not counting yours, with the same number of teams, the same roster size, the same categories and the same wire (FAAB or not). Only their numbers go into the pool, never a roster, a name or a move of theirs, and you are told only how many leagues are in it. Any owner of a league can keep its numbers out of every pool with the switch "Let this league's averages help similar leagues" on League connection; the league still reads the pool of the others.
- The default: the figure measured on the one league the front page describes, until one of the above exists.
The order is the point. Your own choice beats a measurement of your league; a measurement of your league beats other leagues like it; other leagues like yours beat one league that is not yours at all.
How much history a number needs
Below these, your league's measurement is still shown, with its sample, and is not used: a bar fitted on forty mornings is a coincidence, not a measurement.
| Number | Needs at least |
|---|---|
| What a pickup is worth | 100 adds |
| What an open place is worth | 100 team-periods (one team over one matchup period) |
| Each of the three bars | 200 decision points (one team on one morning it could have made a move) |
| The trade number's record | 20 deals |
A pooled number needs the same.
What is the same for every league
A player's projection. In season every page reads Box Out's line: each man's own games this season, leaning on ESPN's projection for him early on. Before the draft the plan offers ESPN's projection or Box Out's blend (ours and ESPN's). A man's line is the same whichever league he is in. What changes is how it is judged: against your categories, your roster and your opponents, which is where every figure above comes in.
Facts about the NBA. How soon a man out injured tends to return, for example, is measured once from NBA box scores, not per league: your league's history says nothing about it that the NBA's does not.
What you see beside each figure
Every figure carries its source and its sample, in words: "measured on this league" with how many adds, team-periods, decision points or deals; "the pool of" so many "leagues like yours"; or "the default, measured on another league". A bar the league's owner set says so, with the date and their reason.
On the example trade page, the record under the trade number reads, as it stood:
This number is a forecast, and here is its record. Over the 55 trades in this league's history that can be replayed, it pointed at the side that did better in 25 of them, judged on the thirty days after the deal.
The limits
- The long step takes hours: about forty minutes a season. Until it finishes, the bars are the fallback, and the page says so.
- A league with little history leans on others until it has its own. A league in its first season uses the pool of leagues like it, or the default, and every figure says which. A pool exists only once two measured leagues share your settings; until then it is the default.
- In a most-categories league the bars are not measured yet. Its moves are ranked by the chance of winning the week's matchup, and the bars were measured in categories, so none is borrowed. What a pickup and an open place are worth are measured again in matchups a week. Every move is shown with its number and none is labelled by a bar, and the trade number has no record there yet. The league's owner may still set a bar of their own.
- The email goes to whoever started the run: the member who connected the league, or whoever pressed Measure again.
- A league is measured again at most once a day, by its owner, from the account page.
- Some leagues are not measured at all. A league scored in points or rotisserie, or one that scores a category Box Out cannot count, is refused at the first measuring step, with the reason.