DFS NBA: Home/Away Splits
There’s a concept that applies to nearly every major sport that is always a bit helpful in daily fantasy: players play better at home than they do on the road. I always have a slight bias for choosing players at home rather than away for precisely this reason. But how much do Home/Away splits really matter in daily fantasy NBA?
I looked at the differences between NBA stats for teams at home versus away since 2013. The table below compares mean team statistics at home with mean team statistics away. The second column is the percent increase or decrease for home compared to away for each stat.
As you can see, in practically every statistical category teams do better fantasy wise at home than away. The three highest home/away splits are in the free throws, assists and blocks categories. Free throws and assists make perfect sense. A team gets favorable foul calls at home, hence they get more free throws. Assists are a somewhat subjective statistic, so stat keepers are a bit more lenient with their home town team.
Blocks have the highest increase though, which didn’t make a lot of sense to me. After doing some research, it seems blocks are a lot more subjective than I thought. This article from a several years ago is a good read on the subject of stat keeping. In the article, they find that stat keepers have a lot of discretion over two statistical categories: blocks and steals. This thread on reddit talks about evidence that Anthony Davis sees inflated block numbers at home.
Reading these articles led me to try a new experiment. Instead of looking at home/away splits for the whole league, I wanted to look team by team to see if some teams showed more bias than others. The results are posted to this table.
If you click on the link above and scan the table, you’ll see a few outliers. Philadelphia and Cleveland both have 17% more assists at home than on the road. They clearly have stat keepers who give a lot of borderline assists. New Orleans also has an obscene amount of blocks at home compared to the road, a bit over 60% more. I looked at Davis alone, his split is similarly large at 45% more blocks at home. But the team number suggests this is not just a team padding their superstars numbers, but instead giving out blocks to their whole team liberally. Charlotte is a close second with nearly 51% more blocks at home.
There are other statistics where teams have larger splits. For example, Dallas shoots 22% more free throws at home compared to on the road, Washington gets 14% more steals at home, and Chicago gets 14% more offensive rebounds. My guess is, for the most part, is that these statistics are mostly noise, meaning they are fluctuations based on randomness. If we look at any type of split for 30 NBA teams, we’re bound to find big splits based on variance alone. I wouldn’t use these statistics for much of anything besides blocks and assists, although offensive rebounds and steals would make some sense to consider.
What do we do with this data? It turns out being at home or away is a very big deal for some teams. For teams that give out a much greater amount of assists and steals at home, you should be inclined to play point guards and shot blockers in home games and be inclined to avoid those players when they are on the road. Players like Anthony Davis, Ish Smith, and Kyrie Irving will be great daily fantasy plays when they play at home and suspect plays when on the road.View all posts by Daniel Steinberg