Wins Above Replacement Player (WARP)

In by NBAstuffer Team

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Wins Above Replacement Player (WARP), is a metric which is invented by Kevin Pelton, who borrowed the approach from Sabermetrics and Baseball Prospectus.

Learn more about WARP calculation.

WARP evaluates a player who belongs to a team which is made up of him and 4 average players. This team is compared to another team made up of, 4 average players and a replacement level player. Using replacement level shows the value of players who can play heavy minutes and avoid injury while continuing to perform above replacement level. Using wins gives a measure of value that is easy to understand and constant over time. Lastly, by eschewing the traditional linear weights method so common in basketball analysis, WARP does a better job of incorporating defensive value.

Like all rating systems based on box-score data, WARP can’t account for contributions that are not tracked in the box score, most notably on defense. It does no better than linear weights methods at evaluating players like Bruce Bowen. Also, it requires a number of assumptions such as the value of assists, the trade-off between usage and efficiency, and replacement level. However, this rating system is very flexible. Players can be rated on a per-minute basis (using the theoretical “winning percentage” of the team with 4 average players), in terms of their offense and defense and in terms of their overall value.

The WARP method also draws heavily on the work of Dean Oliver.