Loading ...
Sorry, an error occurred while loading the content.

Re: Home Team Assist Bias

Expand Messages
  • John Hollinger
    They did the same thing to Webber last year after the Sac scorekeeper gave him a bogus assist to get a triple-double. ... And, ... ... no ...
    Message 1 of 11 , Nov 4, 2003
    • 0 Attachment
      They did the same thing to Webber last year after the Sac scorekeeper
      gave him a bogus assist to get a triple-double.



      --- In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
      wrote:
      >
      > Thanks, Mike, for clarifying what I had little time to explain.
      And,
      > yes, Hakeem did have an assist taken away. They do review such
      > things, though I don't know the full process.
      >
      > --- In APBR_analysis@yahoogroups.com, "Michael Tamada"
      <tamada@o...>
      > wrote:
      > > -----Original Message-----
      > > From: Mike G [mailto:msg_53@h...]
      > > Sent: Sunday, November 02, 2003 3:29 PM
      > >
      > >
      > > --- In APBR_analysis@yahoogroups.com, igor eduardo küpfer
      > > <igorkupfer@r...> wrote:
      > > >> Has this been covered?
      > > >>
      > > >> Ast/FGmade 02-03
      > > >>
      > > >> Home Away
      > > >> Win 62.4% 59.1%
      > > >> Loss 61.2% 57.8%
      > > >>
      > > >> Seems like pretty clear bias against the visitors to me.
      > > >
      > > >Granting assists more liberally to the home team (almost 6% more
      > > >generous, win or lose) might cause someone to think differently
      > > >about a player -- unless they know of this bias.
      > > >
      > > >It's statistically significant, but it doesn't seem important,
      > > >otherwise. Guys play half their games on the road, so there's
      no
      > > >overall advantage.
      > > >
      > > >However, if someone points out that Jamal Crawford gets 5% more
      > > >assists at home, and therefore he should play fewer minutes in
      > road
      > > >games, they are apparently mistaken. That's just par for the
      > > >course: everyone gets 5-6% fewer assists on the road.
      > >
      > > All good points, although I would also take DeanO's point and
      > > drive it even further: it's possible (unlikely, but possible)
      > > that those stats reflect no bias at all, but instead are REAL.
      > >
      > > I.e. maybe visiting teams have fewer assists, percentage-wise,
      > > than home teams. We know already that the visiting teams are
      > > more likely to lose, and will score fewer points. Maybe they
      > > rely more on one-on-one offense to score. Maybe they get
      > > fewer fastbreaks and thus fewer chances for a Payton to pass
      > > to a streaking Kobe for a layin.
      > >
      > > A similar statistic: I believe that researchers have already
      found
      > > that home teams get more Free Throw Attempts, and are called for
      > > fewer fouls, than visiting teams. Is that due to ref bias? Or is
      > > it because the home teams literally are commiting fewer fouls?
      > >
      > > In the case of fouls, my guess is that most of the home-road
      > > differential is caused by real differences and not ref bias.
      > >
      > > In the case of assists, I'd guess that home scorer bias is a
      strong
      > > and quite possibly primary factor, but I don't think we have
      > > evidence to come close to proving this.
      > >
      > > I'd have to think that the NBA has quality control measures for
      > > its scorekeepers and statkeepers, and looks at video tapes to
      > > see if assists are being awarded properly (didn't the NBA take
      > > away a bogus home quadruple-double from Hakeem or someone like
      > > that, after determining that the home statistician had been
      > > over-generous in awarding assists -- or maybe it was even
      > > a phantom rebound)? So the NBA probably does have true
      > > comparative home and road stats. Whether it has found a
      > > home-road difference, how large it is, and how much effort
      > > the NBA is putting into eradicating it -- those are open
      > > questions.
      > >
      > >
      > > --MKT
    Your message has been successfully submitted and would be delivered to recipients shortly.