The Number
The book posts a line. This finds the number where his own three-season record actually crosses fifty-fifty, and shows you the distance between the two.
How the projection is built
Most projections are an average dressed up. This one is not. A player's record is measured at six different lines in each market — for receptions that is 1.5 through 6.5 — and each line has a hit rate attached. Somewhere between two of those lines his rate passes through 50%. That crossing point is the projection.
It is a blunt instrument on purpose. It cannot be talked into a number by a narrative, it rests entirely on games that were actually played, and when there is not enough history to find the crossing point the player simply does not appear rather than getting a made-up figure.
What the distance means
When the projection sits well above the posted line, the market is asking for less than his record suggests. That is a reason to look, not a reason to bet — go to the gap and see whether the price pays for it. A big distance on a thin sample is noise.
Where it goes next
Baseball, basketball and hockey projections need their own measured base. Until that exists, those boards show market numbers only and this page says so rather than inventing one. Read the tape, then the NFL board.