NBA Strategy: Pricing Injury Impact For Non-Replacement Players
As I talked about in this post about injuries, there are a lot of basic and generally accepted ways of determining the impact an injury will have on the fantasy output of other players on the team. The easiest impact to understand is minutes impact: when a starter goes down, another player will be inserted into the starting lineup and be given a lot more minutes. That player, assuming he will contribute on the offensive and defensive end, should cause him to be undervalued, because generally the more minutes a player plays, the greater his fantasy output will be.]
The harder aspects of assessing injury impact is how a players absence will impact the other players who get minutes on the team. People tend to have intuition that Damian Lillard will be a better fantasy player when Lamarcus Aldridge goes down, or Paul Millsap will be better when Al Horford goes down, but logic on why this is the case is not often found. However, I have a simple method of how to assess injury impact on other fantasy contributors on the team, using USG% and rebounds. Generally, if the replacement player has lower USG% than the injured starter, other high USG% players on the team will have increased fantasy output. If the replacement player is a worse rebounder than the injured starter, other good rebounders on the team will have increased rebounding totals, and therefore better fantasy outputs.
Usage percentage (USG%) is the % of a teams possessions where a player made a shot attempt or turned the ball over. Generally, this statistic is correlated with fantasy output, because a player must physically hold the ball on offense to get an offensive fantasy statistic, points and/or assists.
If a player with a high USG% goes down, that means someone else is going to have to hold the ball, and therefore have more opportunities for fantasy points. Normally, the replacement player to a high USG% player, i.e. Al Horford/Pero Antic, Nene Hilario/Trevor Booker, and Lamarcus Aldridge/Dorell Wright, does not command the ball on offense as much as the starter did. This change should be proportional to the change in USG%, distributed across other players in the lineup. Therefore, other players must hold the ball more and be given a greater opportunity to score fantasy points.
A good example of this concept is the recent injury to Nene Hilario. Hilario on the season has a USG% of 23.2. His replacement, Trevor Booker, has a USG% of 14.2. Therefore, we should expect an increase of about 9% distributed across the other players in the starting lineup. Trevor Ariza appears to have gotten the biggest bump, as his USG% has increased from 17% to 20% with Nene out of the lineup. Subsequently, Ariza’s fantasy output has increased by about 3 fantasy points, from 28 to 31 per game.
Below is a list of defensive rebounding % for all 30 NBA teams