These are a few of the frustrations I have with commonly used stats during TV broadcasts of NBA games.
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Field goal percentage. Some shots count for two points, others count for three points, so why are we counting them together? If someone has a 45% FG% is that good or bad? If they shoot only threes, it’s very good. If they shoot only twos, it’s not. This is why effective field goal percentage was created.
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Rebound margin. You will often hear TV analysts say the team that is losing is getting out worked on the glass because they are being out rebounded by x rebounds. But here’s the thing, when you are losing you probably are missing more shots than your opponent. When you miss more shots than the other team, you are likely to be getting out rebounded because the defense is more likely to rebound a missed shot - in 2018-19 the average offensive rebound percentage on missed field goals was 73.6%. Rather than looking at total counts, look at a team’s offensive/defensive rebound percentage to see how a team is rebounding. Note that breaking rebounding down by shot zone is even better. 38% of misses at the rim were offensive rebounded this season while only 20% of missed threes were offensive rebounded.
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Total Assists to measure ball movement. “Only 5 assists in the first half, they need to do a better job of moving the ball” is something you may hear from a TV analyst. To get assists though, you have to make shots. You can have a low assist total simply because you are missing a lot of shots. Assist percentage is a more appropriate stat to use here.
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X points on Y shots. If a player shoots 5/6 on twos, 3/5 on threes and 9/10 on free throws you will hear someone say they scored 28 points on 11 shots. Why are we counting the points scored on free throws but not counting free throws in the number of shots? 28 points on 16 true shot attempts or shooting possessions is a better way to describe the efficiency of this player. Note it could be under 16 true shot attempts if they had some and1s or three point shooting fouls.
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Points off turnovers. Picture the following two situations. An intercepted pass that leads to a breakaway dunk. An offensive foul that stops play and leads to a layup scored against a set defense. Both of these count as two points off turnovers, but in only one case were the points score because of the turnover. Why do we care about how many points a team scores after a dead ball turnover? These are possessions against a set defense and are typically the lowest value possessions. On the other hand, possessions off steals are the highest value possessions. In 2018-19, the league average efficiency after a live ball turnover was 1.28 points per possession and off a dead ball turnover it was 1.08 points per possession. Points off steals would be a better stat to make the point analysts are trying to make here.
It’s 2019, we have better stats we can use.