Home win probability estimates the chance the home team wins from the score, time remaining, home court, and possession. It doesn’t yet account for team strength, so early-game estimates treat both teams as evenly matched.
Percentage-point shift is the change in home win probability since the previous logged event, shown from the associated player’s team perspective, or the event team when no player is identified. Positive values shift toward that team; negative values shift away from it. It is shown for on-court actions, not substitutions or timeouts. Exact zero is shown as 0.0 pp; smaller nonzero changes are shown as <0.1 pp with their direction. The change includes time passing and does not isolate the event’s causal effect.