Part 6 of a series on the NBA’s fading home-court advantage; start with Home Court Advantage Is Fading.
In the playoffs, home court is the better team’s reward, and for nearly four decades the picture held steady: the team with home court won 72–77% of the games it hosted, while its weaker opponent won only about half of the games it hosted. Which mattered more in a playoff game, the better team or the building? In a typical playoff game, the answer was the building. The recent playoff slide belongs mostly to the favourite: in the latest era the team with home court wins less often at home than it did through 2022, while the weaker team’s home rate has slipped only a few points, to about a coin flip. That rests on a single era of games, so it describes the latest seasons rather than a settled trend.
The playoffs are not just a shrunken copy of the regular season. They reach the same decline by their own structure, their own baseline, and their own timeline. What they share is the destination.
The top of that sawtooth is flat: Games 1, 2 and 5 are effectively tied, the host winning 73.8–74.0% of them. Game 5 is the higher seed’s third home game and, in a series level at 2-2, often the one that breaks it, yet it is no friendlier to its host than the first two. And the advantage does not wear off: Game 7 is worth about as much to its host as Game 1, and the three games the lower seed hosts sit near 52% however deep into the series they fall.
The favourite’s edge held, then narrowed
Split every playoff game by which team hosted it. In the 1980s and 1990s, the lower-seeded team, the weaker opponent, won 56% and 52% of their home playoff games. Put as a difference, the higher seed’s home win rate ran about 21 percentage points above the lower seed’s in the 1980s, and stayed 21–24 percentage points above it in every era through 2022. Home court never closed the gap between them.
From the early 2000s onward the lower seed’s home rate sat at 47–52%, while the higher seed’s, which held at 72–77% from the 1980s through 2022, eased to about 65% in recent seasons. So the gap, which peaked at 24 points, is down to 16 in the latest era. Most of that narrowing is the favourite’s: measured against its own level through 2022, the higher seed’s home rate fell more than twice as far as the lower seed’s. The weaker host’s rate barely moved from where it had sat since the early 2000s, and is about a coin flip now. Both readings rest on a single era of fewer than two hundred home games per side, so they describe the latest seasons, not a trend the data has pinned down.
📊 The G1–G7 breakdown from the chart at the top, broken out by era, one line per era. The…
Is it just weaker seeds, or real home-court decline?
A fair objection: maybe playoff home teams win less now simply because top seeds no longer outclass their opponents the way they once did. The data says no. Strip out the quality gap between the two teams and the year-by-year playoff decline doesn’t budge; none of it is explained by seeds bunching closer together. The cleanest test isolates the genuinely weaker team by regular-season quality: when the objectively weaker team hosts Games 3 and 4, it wins about half the time, when on talent alone it should lose. The building roughly cancels the talent deficit in that game, though it never lifts the weaker team to the favourite’s own home rate.
📊 The playoff decline is genuine home-court weakening, not weaker seeds. Left: the yearly…
Does the regular season show the same pattern?
Partly, and over a much longer stretch. In the playoffs the gap between the favourite’s and the underdog’s home rates held for nearly four decades and is smaller only in the latest era, mostly because the favourite’s home rate fell. The regular season is a useful check, because it has far more games in every era.
A 2024 academic paper ran this quality-vs-home-court split for the regular season, so I ran the same one here. Take every regular-season game where the home team’s win rate the year before was at least 10 percentage points above or below its visitor’s. Quality matters here, and always has: today the stronger home team wins 70% of those games, the weaker one only 41%.
The gap between them has narrowed: every home team wins less than it used to, the stronger ones (82% to 70%) slipping about twice as far as the weaker ones (47% to 41%), so the split shrank from 34.9 points to 28.2. That regular-season narrowing is a trend across the whole record, while the playoff gap sat at 21–24 points through 2022 and dropped to 16 only in the latest era, so one era of playoff games cannot yet say whether the postseason has joined the regular season or just had a few unusual years. (The paper that prompted this check is covered in the Related Work companion.)
A best-of-7 absorbs most of home court advantage
A single home game and a seven-game series are very different things. To see how the per-game advantage translates into who actually wins a series, I ran a simulation: take the home win rate for one game and play out 200,000 best-of-7 series between two otherwise-equal teams, with the home-court side hosting Games 1, 2, 5, and 7. The format flattens the advantage. In the earliest era a home team won about 65% of individual regular-season games, but that turned into only a 55% chance of winning a series. By the most recent era the per-game rate had fallen to about 56%, and the series advantage with it, to about 52%: a home-court team in a series is now barely better than a coin flip. The playoffs tell the same story a notch higher, a series advantage near 53% today, though the two are not far enough apart to separate on the playoff games available. What the format changes is the scale, not the story: on the simulation’s own inputs, a 9.3-point drop in the regular-season per-game advantage shows up as about a 3-point drop at the series level, because a best-of-7 leaves the home-court team roughly a third of its per-game edge to begin with. That third applies to the decline as much as to the level: the per-game edge kept 37% of what it had in the 1980s, and the series-level edge kept 38% of its own. The series advantage was not sheltered from the fall; it is simply a smaller thing falling.
Two cautions on the simulation. The playoff per-game rate mixes home court with seeding, since better teams host more games, so the regular-season figures are the cleaner read on the pure venue effect. And the simulation treats each game as a fresh start, unaffected by who won the ones before, so it shows how much the format dilutes an advantage rather than forecasting any real series.
📊 Two panels translating the per-game home advantage into a best-of-7 series advantage via…
Different timing, same direction
The playoffs reached the same place later. The regular season’s bend is locatable, somewhere in the 1990s, while the playoff record shows no bend anyone can locate: postseason home court advantage sat near 64% from the mid-1990s through 2017 and has fallen since. Because each postseason rests on far fewer games than a full regular season, the direction of the playoff decline is clear but its exact size is not. The much-blamed 2014 playoff format change doesn’t explain it: once the long decline is allowed for, the format break adds nothing detectable, an alibi covered in full in The Usual Suspects.
Every playoff building looks alike
One more playoff twist, covered in full in The Altitude Holdouts: the real spread between franchises that shows up in the regular season can’t be detected in the postseason, where the fewer than 150 games most buildings have hosted can’t separate one arena from another. Yet the common advantage every host shares runs larger in the playoffs than in the regular season. That is the playoff paradox in one line: the differences between buildings drop below what the games can detect, and the edge of being at home at all is bigger.
Next: The Altitude Holdouts. Two arenas never got the memo: in the regular season Denver and Utah still punish visitors, and home games keep getting more lopsided in both directions even as home wins shrink.
Back to the series hub: The Disappearing Home-Court Advantage
How this was made: the writing here is mostly AI/LLMs working from my analysis and direction; the numbers are all Python on public NBA data. Every claim is backed up by data. The data, analysis, and conclusions are trustworthy. The full note is on the series hub.
Data: NBA.com Stats, pulled with the open-source nba_api tool; attendance records from Basketball-Reference.