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

811Re: Assigning Credit to Players

Expand Messages
  • HoopStudies
    Mar 29, 2002
    • 0 Attachment
      --- In APBR_analysis@y..., "dlirag" <dlirag@h...> wrote:
      > >
      > > One of the things I remember hearing about Dominique Wilkins and
      > have
      > > heard about Allen Iverson is that their shots are more often
      > > rebounded by their own team because their teammates know that
      they
      > > are going to shoot the ball. We already have put forth evidence
      (I
      > > think, I know I did the work) showing that Iverson's presence
      does
      > > help the Philly offense even though the boy sometimes can't hit
      the
      > > side of a barn with his shot.
      >
      > A shot can be seen as a pass that results in one of the following
      > things happening: 2 or 3 points are immediately scored (45%
      chance),
      > the ball ends up in a teammate's hands (16% chance), or the ball
      goes
      > to the opposing team (39% chance).

      This gets at what Gary Skoog did in one of James' abstracts, where
      they assessed the expected runs for every given state and assigned
      credit/blame for transitions between those states.

      At the point before a shot, every possession is worth about 1 pt.
      After the shot, it could go to 2 pts with a made shot and end of
      possession, 3 pts with a made shot and end of possession, rare cases
      of >3 pts with or without continued possession, 0 pts with the
      probability of an offensive rebound (expected value of 1 pt after
      OR), 0 pts with probability of opponent getting the ball (expected
      value of 0 after DR). In the 0 pts with offensive rebound, you
      diminish the value of the missed shot by about 2/3 (assuming 1/3
      chance of OR), so, using relative to the mean credit (as Skoog did),
      the credit is -2/3 to the shooter who missed (bring expected points
      from 1 to 1/3), 2/3 to the offensive rebounder (who brought it back
      to 1), then 1 to the scorer (for going from 1 to 2). If this
      methodology is carried out in detail, you could modify the shooter-
      specific OR%, so that rather than diminishing Iverson's misses by
      2/3, you diminish them by 1/2 if you think that half of his misses
      are rebounded by the offense.

      Though in this case the rebounder and scorer are the same, note that
      there is more relative credit to the scorer (+1) than to the
      rebounder (+2/3). This may be in conflict with what the offensive
      rebound studies we did earlier here said, but I'd need to check.

      Dean Oliver
    • Show all 10 messages in this topic