Continuing a series I started with college basketball, I’ll now analyze what I call True Home- and Road-Court Performance in the NBA. As I’ve reasoned in the last two issues of “Point Spread Weekly,” one of the most important factors in analyzing basketball teams’ strengths is determining how much they should be assigned based on playing at home or on the road. The only ways to do this, in my opinion, are with a standard designation or a team-specific assignment. I prefer the latter, as I believe that specific performance trends warrant treating each team individually from theoretical and numbers standpoints. After all, some environments naturally are tougher than others.
For those who like to keep things simple, know that in his latest ratings, Jeff Sagarin proclaims the average NBA home-court advantage is 2.33 points. In studying the numbers over the last 2 1/2 seasons, I have found it to be just a bit higher, specifically 2.36 points. My own home- and road-court ratings reflect that number, and they are built into the Strength Ratings you see in “PSW” each week or on VSiN.com on command.
Bettors almost have to do the team-specific method because certain teams have clearer home-court advantages than others. Among these are crowd capacity and enthusiasm, the quality of the team, the style a team plays and even the distractions to visiting teams. That last factor seems to be a bigger issue in the pros than in college. But one thing is certain: No way is every team’s advantage the same.
Judging home-court edges as equal across the board can lead to mistakes and missed opportunities — or even worse, losses. For instance, the variance I assign for the 30 NBA teams is as high as 1.1 points. For those who regularly play the NBA, you know how close the final scores can come to the point spreads, so each point is important.
To determine which teams hold the best True Home- and Road-Court Performance in the NBA, I have taken game logs at home since the start of the 2017-18 season, or essentially the last 2 1/2 seasons, and have compared teams’ own average power ratings in those games to their opponents’ average power ratings, using my actual logged numbers. This margin would be considered the amount the team should have won or lost by when meeting on a neutral court, or the expected margin. I then compared this amount to the actual point differential the team accumulated in those games. Obviously, teams with a greater actual differential than expected differential played the best at home or away. For NBA teams, the margins ranged from + 5.2 for Philadelphia to -0.7 for Cleveland at home and from -0.8 for Dallas to -4.5 for Washington on the road.
Of course, you would not want to assign a home-court edge of 5.2 points to the 76ers at home, as that could put you in a bind for future games. However, you should respect Philly anytime it plays at home until things change noticeably. Similarly, you wouldn’t want to discredit Cleveland for playing at home, but considering the Cavaliers have been more than 3.0 points worse than the average home NBA team in recent years, you wouldn’t want to assign the blanket 2.5 either.
In general, using the average closing line for the last 2 1/2 seasons, it indicates that bookmakers will assign about 2.52 points in an NBA game to a home team. Again, my numbers average out to 2.36. That slight difference accounts for road teams having gone 50.75% against the spread in that span.
Importantly, I don’t specifically assign my own home- and road-court ratings exactly with the order of the True Ratings, as I also give strong consideration to the straight-up and ATS records as well as the perceived difficulty of playing at a particular venue. That said, Philadelphia and Denver command my highest home numbers, while Cleveland, Chicago and Phoenix are assigned the fewest. As far as the road ratings, Dallas, the Clippers and New Orleans are assigned the most, while Washington and the Nuggets receive the least.
Let’s take a quick look at some of the highlights of the study.
NBA Home-Court Performance Study Highlights
— The team with the highest true home-court performance rating over the last 2 1/2 seasons is Philadelphia at + 5.2. The 76ers would have been expected to win their 116 home games in that span by 3.5 PPG if played on a neutral court yet are winning by 8.7 PPG, producing an advantage of 5.2 points. Denver (+ 4.4), Utah (+ 4.2), San Antonio (+ 4) and Toronto (+ 4) are the other teams at + 4 or better.
— The Nuggets own the best outright winning percentage of any team at home in this study, having gone 89-26, or 77.4%. That ranks slightly ahead of Philadelphia, Houston and Toronto, all of which round out to 77%. The Rockets have been expected to win by the greatest amount and have played to the largest point spreads of any team at -8.1, which is why their true rating isn’t as high as the others.
— Philadelphia’s 68-46 ATS record during this study is the league’s best. Boston, at 67-51 ATS, and Indiana, at 60-47 ATS, are the only other teams better than 55%.
— Houston’s 115.7 PPG scored and Utah’s 101.3 PPG allowed are the high benchmark scoring figures in home games since 2017.
NBA Home-Court Performance Study Lowlights
— The team with the lowest true home-court performance rating over the last 2 1/2 seasons is Cleveland at -0.7. The Cavaliers would have been expected to lose their 119 home games in that span by 2.7 PPG if played on a neutral court but are losing them by 3.4 PPG, producing a disadvantage of 0.7 points. Chicago (-0.5) and Phoenix (-0.2) are the other teams with negative ratings.
— The Suns actually own the worst outright winning percentage of any team at home in this study, having gone 31-76, or 29%. That ranks below New York and Chicago among teams below 35%. The Suns and Hawks have been expected to lose by the greatest amounts, according to the average point spreads, at + 3.8 for each.
— Cleveland’s 45-72 ATS record during the 2 1/2 years of this study is easily the league’s worst. Phoenix, at 42-64 ATS, and Golden State, at 50-75 ATS, are the only other teams at 40% or worse.
— Chicago’s 103.8 PPG scored and New Orleans’ 114.5 PPG allowed are the low benchmark scoring figures in home games since 2017.
NBA Road-Court Performance Study Highlights
— The team with the highest true road-court performance rating over the last 2 1/2 seasons is Dallas at -0.8. The Mavericks would have been expected to lose their 104 road games in that span by 2.1 PPG if played on a neutral court yet are losing them by only 2.9 PPG, meaning being on the road costs them only 0.8 PPG. New Orleans (-0.9) and Toronto (-0.9) are the other teams at -1 or better.
— The Raptors actually own the best outright winning percentage of any team on the road in this study, having gone 77-46, or 63%. That ranks slightly ahead of Houston and Milwaukee of the teams better than 58%. The Bucks have been expected to win by the greatest amount at 5.1, which is why their true rating isn’t as good as the others.
— Dallas’ 60-42 ATS record during the span of this study is the league’s best. Miami, at 61-44 ATS, and Brooklyn, at 61-45 ATS, are the only other teams better than 57%.
— Golden State’s 112.6 PPG scored and Boston’s 104.6 PPG allowed are the high benchmark scoring figures in road games since 2017.
NBA Road-Court Performance Study Lowlights
— The team with the worst true road-court performance rating over the last 2 1/2 seasons is Washington at -4.5. The Wizards would have been expected to lose their 111 road games in that span by 1.3 PPG if played on a neutral court but are losing them by 5.8 PPG, producing a disadvantage of 4.5 points. Denver (-4.4) and San Antonio (-4.1) are the other teams with true road ratings worse than -4.0.
— The Hawks actually own the worst outright winning percentage of any team on the road in this study, having gone 25-83, or 23%. New York is the only other team below 25%. The Suns join the Knicks and Hawks as teams expected to lose by the greatest amounts, according to the expected power rating differentials, at 6.0 or more for each.
— Three teams share league-worst ATS percentages of 44%: Washington, Denver and Philadelphia.
— New York’s 102.7 PPG scored and Phoenix’s 115.9 PPG allowed are the low benchmark scoring figures in home games since 2017.