March 13, 2017, 3:00 am
GPPs are often won and lost based on which games stay close, which games become blowouts, and which games go to overtime. Vegas Lines help DFS players predict which outcomes games are likely to see.
This article will use Vegas data from 2008-2009 to the present to gain a deeper understanding of how Vegas spreads can help us predict game outcomes. We’ll be looking for answers to the following questions:
- Quantitatively, how much does the spread affect the chances of a blowout?
- Can we use spreads to help predict overtimes and to what degree?
- To what degree does an underdog being at home mitigate blowout risk?
Point Differential vs. Vegas Spread
Here are the historical score differentials based on spreads at the end of regulation:
Some notes and general takeaways
- There is overlap in the ranges. For example, the 0-2 group and the 2-4 group both include games with a spread of 2. This is so this article can both look at as many ranges as possible while keeping the sample sizes large enough to be significant. 12 point spreads are not included in the >12 range
- The point differentials are not assuming the favorite is up. For example, an 8 to 10-point spread resulted in a 1 to 4-point game 15.6% of the time. This does not mean the favorite wins by this margin 15.6% of the time. The 15.6% includes times where the underdog wins by 1 to 4 points.
- NBA games with spreads between 6 and 8 behave very much like the average of all games. We see the 6-8 row very nearly matches the all games column. This gives us a benchmark when thinking of spreads. We should consider a spread around 6-8 an average spread, above 8 a high spread, and below 6 a low spread.
- The odds of OT are very much dependent on spread, but perhaps less so than one would think. The trend of lower spreads leading to more overtimes is very evident. About 1 in 12 games with a spread of 2 and lower will result in an overtime. 1 in 25 games with a spread between 10 and 12 going to overtime is not insignificant, however.
- NBA games are very hard to predict. Spreads very much do not guarantee close games or blowouts. 27% of games with a spread within 2 finish with a team winning by over 12. 5% of games with a spread greater than 12 finish within 8.
- Any Game can get out of hand. In every range, more games turn into 21+ point blowouts more often than they go to overtime.
3rd Quarter Point Differential vs. Vegas Spread
The 3rd quarter point differential can provide greater insight into the nature of blowouts than the regulation differential. Intuitively, teams that have the game in hand can let off the gas and give back points in the 4th. Blowouts are often fine in cash games, so long as the game doesn’t hit blowout territory too early.
This is especially true for a very high usage player playing as the favorite, who often will be the reason a game turns into a blowout at all. Late blowouts can also be managed well if a player’s minutes are staggered so they play at the beginning of the 4th quarter with the second unit before the rest of the starters come back into the game.
The 3rd quarter spread vs. Vegas spread can give insight into how likely a game is to stay close- at least long enough for our cash game plays to get some 4th quarter run.
Here is the 3rd quarter point differential compared to the Vegas Spread:
Some takeaways from this data
- NBA games are very hard to predict. We’ve already mentioned this above, but it can’t be overstated. Nearly 26.2% of games with spreads between 0-2 had potential blowouts brewing with point differentials of 13 or greater.
- Point spreads over 12 are extremely risky. One thing that stands out here is the comparatively massive 23.5% chance of a game with a 12 point or higher spread being out of hand. Only 3.5% of all games have spreads this large, so it makes sense that these games would represent the biggest mismatches in the NBA. The sample size is relatively small, but a differential of 21 points or more going into the 4th happens 32.1% of the time in games with spreads over 14.
- Games tend to have similar risk of blowouts until the spreads reach double digits. Note how flat percentages of a game being out of hand or close to being out of hand are until the 10-12 range. The intuition that 10 point and larger spreads are when blowouts get a little worrisome is not just a bias towards fearing double digits, but backed up by the data.
Blowout risk: Home vs. Road
DFS players commonly believe home underdogs are in position to keep games closer than underdogs on the road. As the following chart shows, it is true home dogs get blown out less than road dogs.
This chart is a bit misleading in the sense that teams tend to be bigger favorites when they are at home compared to when they are on the road. Below are the charts for games with a home dog, games with a road dog, and difference between the 2 in each spread tier.
After adjusting for spread, we see home dogs get blown out slightly more than road dogs, contrary to DFS’s general wisdom. This is almost definitely noise, but it shows there is likely no significant increase or decrease in the likelihood of a team getting blown out based on their home or road status independent of spread.
The Golden State Warriors
With their fast pace and consistently large spreads, the Golden State Warriors are the team with the most potential benefits if one can accurately predict their blowout risk. While there will unfortunately never be a single-team sample size large enough to be sure, the Warriors produce a chart so odd that it is very much worth sharing.
This is since the Steve Kerr era in Golden State began. Note the hilarious amount of 21+ blowouts in games with spreads less than 4. Though the sample size is too small to make any serious conclusions, there does seem to be indication Golden State may carry a higher risk of blowout independent of spread.
Recap and Additional Findings
- When looking to see if the increased volume of 3-point shots over the years has increased the likelihood of blowouts independent of spread, no conclusion was reached. If there is an increase in blowout risk it is very small, if not entirely negligible.
- When looking to see if pace increases or decreases the likelihood of a blowout, we discovered a somewhat significant correlation between high paced teams and blowouts. The sample size was not large enough to make any claims with a high degree of certainty, but it could be something to keep in mind.
- Blowout risk is relatively similar for all spreads until it nears and eclipses 10. Blowout risk ramps up quickly as spreads get larger than 10.
- Point differentials in NBA games are very volatile regardless of spread.
- The home-road status of the underdog does not significantly affect the likelihood of a blowout.
July 2, 2020, 9:02 pmKawhi LeonardSF, Los Angeles Clippers
The Clippers closed their practice facility in a precautionary move after a member of their Orlando traveling party tested positive for COVID-19 on Thursday.
This seems like something that will continue to happen as we prepare to move teams into the Orlando bubble. We'll keep an eye on whether any specific player is infected and how that will impact the restart plans for this team.
Source: Adrian Wojnarowski on Twitter
July 2, 2020, 4:49 pmStephen CurryPG, Golden State Warriors
According to Adrian Wojnarowski and Jackie MacMullan of ESPN, the NBA is close to signing off on a secondary bubble location in Chicago for the eight teams left out of the league resumption with a target date of September.
They went on to say that this bubble would allow those eight teams who were not invited to Orlando to have an opportunity to have mini-training camps as well as games. It has been reported throughout the last few months that the teams that were not invited should have an opportunity to prepare for next season. Many of the teams who were not included would benefit greatly from additional practice time and game reps as most of these teams have young players who need to continue to develop their skills. There will still be a lot of logistics that need to be ironed out so this a situation to monitor as we learn more.
Source: Adrian Wojnarowski on Twitter
July 2, 2020, 4:01 pmMarvin Bagley IIIPF, Sacramento Kings
Marvin Bagley confirmed that he is "ready to go" for the NBA restart in Orlando after rehabbing from a left foot sprain.
It was previously reported in early July that the Kings' training staff believed that Bagley would be available for game action soon and this report confirms that Bagley will in fact be available for the league resumption. Bagley has yet to live up to the hype of the second overall pick in 2018 as he has only been able to play in 75 out of a possible 146 games (51.3 percent). It is unclear what role Bagley will have in Orlando but it appears that his injury woes are behind him and we will learn more about his ability during the league resumption. Bagley's return would likely cut into the playing time of Nemanja Bjelica, Harry Giles, Jabari Parker and Harrison Barnes.
Source: Sean Cunningham on Twitter
July 2, 2020, 2:57 pmJusuf NurkicC, Portland Trail Blazers
In a conference call with Portland media, Terry Stotts revealed that Jusuf Nurkic and Zach Collins are likely to return to their starting jobs and won't be under minutes restrictions when the NBA resumes.
It should be a huge defensive lift for a Blazers squad that gave up points like crazy, though this will throw a wrench into plans for DFS players. Stotts mentioned that he's considered starting Nurkic next to current starter Hassan Whiteside, though that fit would likely only be tenable in certain matchups. This, plus news of Trevor Ariza's absence during the restart, also has big effects on the wing rotation, where it sounds like Carmelo Anthony and Gary Trent Jr. are competing to start with Nassir Little and Mario Hezonja also in the mix off the bench. This is a big blow to Hassan Whiteside's fantasy appeal — a top-15 player in 31.3 mpg this year– as his minutes should sink into the mid twenties. Anyone participating in a short league that covers the restart may want to view Whiteside as more of a middle-round, blocks specialist type, though this all obviously hinges on how Nurkic and Collins look when games begin.
Source: The Athletic
July 2, 2020, 12:59 pmDevin BookerSG, Phoenix Suns
Monty Williams said that he wants to play Devin Booker and Ricky Rubio less than their typical minute allotment when the NBA resumes in Orlando.
The Suns have extremely slim playoff hopes and Williams doesn't want to risk one of the team's starting guards sustaining an injury in what amounts to a meaningless game. Expect similar moves from plenty of teams who realistically have no shot at the playoffs, even if they don't declare as much publicly. Anyone playing fantasy games for the eight-game restart should familiarize themselves with the depth charts on such teams and maybe downgrade some of the bigger names in case their minutes are limited.
Source: Valley Tales
July 2, 2020, 12:43 pmLeBron JamesSF, Los Angeles Lakers
Out of 344 players tested between June 24-29, nine have tested positive for COVID-19.
That brings the NBA up to 25 positive cases among players since June 23 testing began, a positive rate of 7.1%. 10 out of 884 staff members have also tested positive. How the NBA handles any potential spread of the virus inside the Orlando bubble will make or break their entire plan.
Source: Shams Charania on Twitter
July 2, 2020, 12:39 pmJontay PorterC, Memphis Grizzlies
Grizzlies coach Taylor Jenkins said that rookie Jontay Porter may be available for games in the Orlando bubble.
Porter missed the entire 2018-19 college season after suffering a knee injury and hasn't suited up as a pro, so if he accompanies the Grizzlies to Orlando it'll be more for the experience than actual playing time. His college numbers were intriguing but Porter is only of consequence in deep dynasty formats for now.
Source: Daily Memphian
July 2, 2020, 12:34 pmGrayson AllenSG, Memphis Grizzlies
Grayson Allen (left hip) may be able to play when the NBA season resumes in Orlando.
Allen has been sidelined with left hip soreness since leaving a game in late January, and his ailment would've ended his season had things finished as scheduled. While he hasn't received the all-clear yet, the Grizzlies will evaluate him after he gets through some practices in the Orlando bubble. He's unlikely to play much even if he can, as the Grizzlies currently boast a fully healthy roster.
Source: Daily Memphian
July 1, 2020, 8:28 pmDwight HowardC, Los Angeles Lakers
Dave McMenamin of ESPN reported that Dwight Howard remains in his Atlanta-area home and the Lakers hope he will eventually join them in Orlando.
The Lakers do not plan to replace Howard on the roster. They are being patient with Howard, but if he decides to not play in Orlando the Lakers will likely look to sign another center.
Source: Dave McMenamin on Twitter
July 1, 2020, 7:40 pmLuc Mbah a MouteSF, Houston Rockets
Shams Charania reported that the Houston Rockets plan to sign Luc Mbah a Moute for the Orlando restart.
Thabo Sefolosha announced on Wednesday that he will not participate in the Orlando restart, leaving the Rockets with a need for an additional three-and-D wing. Mbah a Moute played 61 games for the Rockets in 2017-18 and averaged 25.6 minutes per game, so he is familiar with their system. Mbah a Moute will be a low-usage player that the Rockets can plug in at the end of their rotation and will provide them more depth, which could be imperative for teams given the COVID-19 concerns surrounding this Orlando restart.
Source: Shams Charania on Twitter