The NBA introduced a new metric this year called expected field goal percentage (xFG%). Basically, the NBA tracks on-court variables such as defender proximity, shot location, movement, among others, and inputs them into a model to predict the field goal percentage of an average NBA player would be expected to make given those variables. xFG% is a useful stat to evaluate shot quality rather than shot outcome (FG%) and, with context, can tell you whether a player is underperforming, outperforming, or simply taking harder or easier shots. The NBA wrote an article on it, if you’d like to read in more detail. I’ve linked it below. I used Kon Knueppel to compare to Coop given what has been said (at least on r/nba) about Knueppel being the ROY.

Coop’s (stats shown below) xFG% is higher than his actual FG%, at a difference of -2.3%. This tells me a couple things: (1) Coop is creating good looks but his shots just aren’t falling and (2) Coop is underperforming his shot quality, and if he maintains his shot quality his FG% will naturally improve as the season progresses.

FG% = 46.2%

xFG% = 48.5%

FG%+ = -2.3%

Another rookie Knueppel (stats shown below) is outperforming the quality of his shots.

FG% = 47.0%

xFG% = 41.5%

FG%+ = 5.5%

When comparing the two rookies, their xFG% suggests Coop is creating noticeably better shots than Knueppel. What makes this more interesting is that Coop’s actual FG% is only 0.8% lower than Knueppel's despite the significant gap in shot quality. In other words, Coop is nearly matching the efficiency of Knueppel who's outperforming his shot quality, and by many accounts the best shooter in the class. This implies Coop has much more room to grow, while Knueppel has more room to regress as the season progresses.

A higher xFG% than FG% also seems to suggest the player may just be a good tough shot maker. Jokic has a FG%+ of 15.3% and Luka has a FG%+ of 7.8%, both of whom are known as elite scorers. Although Luka has an xFG% of 39.7%, suggesting he’s had some pretty bad shot quality up to this point in the season. However, this doesn’t really surprise me. Luka has always seemed to be a bad shooter when he’s open. Obviously this is a small sample size for both this season and the metric in general and context is essential when analyzing a player based on this stat. It’ll be interesting to see how it evolves.

Intro to Expected Field Goal Percentage

5 comments

  1. I’m just glad we’re seeing some actual basketball talk + deserved Cooper Flagg glaze in this sub. It cannot be overstated just how screwed we’d be without him. I am worried about the tank though. This team is wayyyyyy too good to be a bottom-feeder once we get our guys back.

  2. Teams are playing off of Coop and giving him space. They are going under screens and giving him open shots/mid range looks in an effort to keep him out of the paint.

    Kon has been making everything so defenses are playing him much tighter and not giving him nearly as much space.

    It makes sense that Cooper’s shot quality would be better than Kons. I’m not sure there’s much else to read into this when comparing the two players.

    Coop has not shot well on open shots. Kon has been making contested shots. Defenses will change and react to these guys as they progress in the season. If Coop starts making open shots, his shot quality will certainly start to go down as teams give him less space.

  4. You can’t be seriously comparing Coop’s and Kon’s efficiency by using FG% lmfao. Kon is a volume 3pt shooter and his true shooting % is so much higher than Coop’s

  5. I think you need to switch xFG and FG in the following sentence:

    “A higher xFG% than FG% also seems to suggest the player may just be a good tough shot maker.”

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