Start +/-

Definition. Goals whose sequence began while the player was on the ice, for and against, including the ones scored after he had changed off.

Inputs. events (measured), shifts (measured). Built from. Play-by-play in order: a sequence starts at the last puck gain, at most 25 seconds before the goal.

Constants. sequence window = 25 s (where this number comes from) (a convention; the card shows the top-30 at 15, 25 and 35 s (where this number comes from)).

Reliability.

Not measured yet: not among the measured reliabilities (where this number comes from).

Validity.

Not measured yet: no next-season outcome is defined for this measure yet (where this number comes from).

Uncertainty.

Not measured yet: no bootstrap intervals for this measure (bands exist for Drive, its offence and defence splits, and RAPM) (where this number comes from).

Shrinkage.

shown raw; shrinkage is for rates whose sampling variance dominates (where this number comes from)

Bias ledger.

Slices tested

103 across 621 players; control R² 0.46 (where this number comes from)

Survive FDR

shoots=not on file (34, -0.263); ageBand=<=22 (82, -0.205); ageBand=23-26 (164, +0.127); ageBand=not on file (31, -0.308); club=ANA (20, -0.278); club=BOS (20, +0.613); club=BUF (20, +0.596); club=CGY (21, -0.339); club=CHI (21, -0.359); club=COL (18, +0.585); club=DAL (19, +0.622); club=FLA (19, -0.328); club=MIN (18, +0.352); club=NJD (18, -0.399); club=OTT (19, +0.293); club=PIT (18, +0.325); club=SJS (20, -0.538); club=STL (21, -0.421); club=VAN (20, -0.826); club=WPG (21, -0.354); club=WSH (19, +0.306); arena=Amerant Bank Arena (19, -0.328); arena=American Airlines Center (19, +0.622); arena=Ball Arena (18, +0.585); arena=Canada Life Centre (21, -0.354); arena=Canadian Tire Centre (19, +0.293); arena=Capital One Arena (19, +0.306); arena=Enterprise Center (21, -0.421); arena=Grand Casino Arena (18, +0.352); arena=Honda Center (20, -0.278); arena=KeyBank Center (20, +0.596); arena=PPG Paints Arena (18, +0.325); arena=Prudential Center (18, -0.399); arena=Rogers Arena (20, -0.826); arena=SAP Center at San Jose (20, -0.538); arena=Scotiabank Saddledome (21, -0.339); arena=TD Garden (20, +0.613); arena=United Center (21, -0.359); draftRound=not on file (31, -0.308); contract=ELC (55, -0.216); contract=UFA (253, +0.151); contract=not on file (49, -0.194); capTier=not on file (64, -0.164) (where this number comes from)

• note no structural lean was tested for this measure; see the top-level findings (where this number comes from)

Sensitivity.

items

(constant: sequence window, variants: (builtAt: 2026-09-29T12:11:49.695Z, season: 2025-26, constant: sequence window (seconds back to the last puck gain), variants: 3 fields, rankBiasedOverlapTop30: 3 fields, mostMoved15to35: 8 items, reading: The window matters: top-30 rank-biased overlap is 0.596 between 15 s and 35 s and 0.8 between 25 s and 35 s (1 = identical lists), and the number of goals that get a start moves from 5127 to 7082. Start +/- is therefore shown with its window named, and the card treats 25 s as a convention, not a finding.)) (where this number comes from)

Limits. A long possession with several gains is credited from the last one.

Signed by Chief of measures (data desk); weekly card review; full assay each season; last assay 2026-10-18; test record.