Stat Geek Perspective: NFL Win Total Over/Under Predictions
August 19, 2011 - by David Hess
posted in NFL
Last week in this spot we took a look at the NFL Futures market, and found some value on Super Bowl and Division win odds. We purposely ignored team win totals, because we wanted to devote a whole post to those. Well, by “whole post” we mean this one right here. Let’s get to it.
The table below lists some important information that we’ll refer to in our analysis. For each team, it shows:
- Our predicted season win total for the team, taken from our NFL projected standings. (For more info, see our season projections methodology)
- The Pinnacle* win total for each team.
- Our projected odds for each to team win more than (Over), less than (Under) or exactly the same number as (Push) the Pinnacle win total.
- Our pick for which side (Over or Under), if any, has the best value for each team, along with the current available odds from Pinnacle. (Note that the odds play a huge role here. Even if we project that a team will go Over their win total, if the payout for betting Over is low, it could still be a poor bet.)
- A quick Confidence rating for each pick, on a scale of 1 to 3 stars. (Actually, it’s 1 to 3 “at symbols”, since “@” shows up better than “*”.)
Here’s the table, then we’ll discuss a few of our choices, and a couple things to keep in mind when making your own picks.
|Atlanta Falcons||10.4||10.5||46%||54%||0%||Over +145||@|
|Baltimore Ravens||10.9||11.0||41%||46%||13%||Over +188||@|
|Buffalo Bills||7.3||5.0||73%||18%||10%||Over -164||@|
|Carolina Panthers||6.6||4.5||76%||24%||0%||Over -121||@@@|
|Cincinnati Bengals||8.4||5.5||81%||19%||0%||Over -114||@|
|Cleveland Browns||5.3||6.5||38%||62%||0%||Under +117||@@|
|Denver Broncos||6.7||6.0||54%||34%||12%||Over +125||@@|
|Detroit Lions||6.8||7.5||42%||58%||0%||Under +127||@@|
|Green Bay Packers||10.8||11.5||39%||61%||0%||--||--|
|Houston Texans||6.9||8.0||33%||56%||12%||Under +193||@@@|
|Indianapolis Colts*||8.7||9.5*||39%||61%||0%||Under +105||@|
|Kansas City Chiefs||6.7||8.0||30%||58%||11%||--||--|
|Miami Dolphins||9.6||8.0||61%||28%||11%||Over +145||@@@|
|Minnesota Vikings||8.2||7.0||58%||30%||12%||Over -103||@|
|New England Patriots||10.3||11.5||33%||67%||0%||Under -105||@|
|New Orleans Saints||9.4||10.0||36%||52%||12%||Under +105||@|
|New York Giants||9.6||9.5||51%||49%||0%||Over +128||@|
|New York Jets||8.5||10.0||27%||62%||11%||Under -130||@|
|Philadelphia Eagles||8.7||10.5||28%||72%||0%||Under +143||@@|
|San Diego Chargers||9.3||10.0||34%||54%||12%||Under +120||@@|
|San Francisco 49ers||7.6||8.0||38%||50%||12%||Over +166||@|
|Seattle Seahawks||6.2||6.5||48%||52%||0%||Over +157||@|
|St Louis Rams||5.2||7.5||25%||75%||0%||Under -123||@@|
|Tampa Bay Buccaneers||6.2||8.0||26%||64%||10%||Under -147||@|
|Tennessee Titans||8.9||6.5||76%||24%||0%||Over -130||@|
|Washington Redskins||6.7||6.5||54%||46%||0%||Over +177||@@|
*Almost all the win totals used above came from Pinnacle, and were collected this morning (August 19, 2011). The one exception is the line for the Indianapolis Colts. Pinnacle didn’t offer a line (perhaps due to question marks surrounding Peyton Manning’s health?), so we went to Bodog for the Colts’ win total and odds.
Houston Texans Under 8 at +193
A large part of the value here comes from the long odds on the Under, and the fact that the line sits right on 8, rather than a half a point in either direction. With Under 8, you basically need to compare the odds that the Texans go 7-9 or worse (losing record) to the odds that they go 9-7 or better (winning record). And because the Under odds are +193, in order for an Under wager to break even, they only need to have a losing record a little more than half as often as they have a winning record.
Last year, the Texans were a bit unlucky to go 6-10, and they’ve upgraded their defensive talent and added Wade Phillips as their defensive coordinator. But let’s say the luck was worth 1 win, and improving their defense was worth 2 (a tad generous, if you ask us). That gets them to 9-7. But their schedule this year projects as the 8th toughest, compared to their 23rd ranked strength of schedule last season. That knocks them back down a bit. The bottom line is, even an optimistic projection has them slightly better than average, but they need to be significantly better for the Under not to have value.
Miami Dolphins Over 8 at +145
Last year, Miami went 7-9 against the 8th toughest schedule, while having one of the worst turnover margins in the NFL. Their schedule should be a bit easier this season, and they’re unlikely to fare as poorly as last year in terms of turnovers. Plus, our research has found that the maturation of draft classes from three and four years is a significant positive factor, and Miami had several high-value picks those years. Similar to the Texans, the good price for the Over also contributes to our pick. Even if we’re overly optimistic, there’s a lot of room for error at +145.
Carolina Panthers Over 4.5 at -121
As we mentioned yesterday on Twitter, Jason Lisk made a great case for the Panthers. To summarize his post, teams that suffer a precipitous drop — like Carolina in 2010 — usually bounce back the next year, and end up averaging more than 6 wins. This agrees with our research, which is why team ratings from two and three years ago are included in our preseason rating projections, and why we’ve been predicting Carolina to finish with 6 or 7 wins.
Tips on Totals
Pay attention to the odds, not just the total itself.
You might look at the table above, see that we project the Packers with a 61% chance to go Over 11.5 wins, and think “why don’t they have Packers Over 11.5 as a pick?” The reason is that the odds on the Packers Over are -152, which means you’d have to bet $152 to make a $100 profit. That translates to a break even point of 60% — Green Bay needs to have a greater than 60% chance to go Over 11.5 in order for this bet to have value. Our projection that this would happen 61% of the time isn’t significantly different, so we don’t see any value here.
Keep in mind that totals wagers tie up your money all season.
If you’re just betting for fun, this may not matter to you. But if you’re betting to try to grow your bankroll and turn a profit, this is important. You won’t be able to use the money you have tied up in totals to make other bets, which means you won’t be able to make any profit from it while it’s sitting in the sports book’s account. As a result, you’ll probably want to have a higher threshold for totals bets. A small edge that’s high enough for you to bet on a single game might not be worth it for totals. You’ll likely want to restrict yourself only to bets where you feel you have a large edge.