How To Use Vegas Odds for Fantasy Football (2023)

Fantasy football and betting, both in content and analysis, are so intertwined these days. Analyzing one can often help to succeed in both facets.

Furthermore, fantasy football managers should always be on the lookout for that extra edge that can turn their team from a contender into a champion. While player projections and rankings are a valuable resource, other factors can be leveraged to gain an advantage in the virtual gridiron battle.

In this article, I delve into the world of game spread and player props, shedding light on how they can complement traditional player projections and help you build a winning roster.

As with most things, using Vegas odds should not be the end-all-be-all for making your lineup decisions. Instead, they should be used as another data point and as a way to break ties for difficult lineup decisions. Furthermore, you should mostly be considering cases at the extreme ends of the spectrum.

For example, the difference between a team favored by 2.5 points and a team favored by 4.5 points is not nearly as meaningful of a difference between a team favored by 7.5 points and one as a 3.5-point underdog.

Consistency Series: QB | RB | WR
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2023 Fantasy Football Draft Kit

How To Use Vegas Odds for Fantasy Football (2023)

Unless otherwise specified, the data I’ve presented is from nflfastR and uses regular-season stats since 2013.

Game Spread

Perhaps the most widely-cited and known betting value each week in the NFL is the point spread of a game. The chart below compares a team’s spread to how many fantasy points a player scored in that game.

(Note: The y-axis is reversed to show favorites at the top and underdogs at the bottom.)

As you’ll see, this dispels a common narrative that you want to target passing games for teams projected to be down by a lot. The thought here is that if they’re down by a lot, they’ll have to throw the ball a lot.

Intuitively, this makes sense, but it ignores the fact that a team down by a lot likely won’t have had success passing the ball previously (which is why they’re trailing). Conversely, favored teams are favored for a reason: They are good teams that can move the ball.

Alas, the impact (or lack thereof) that the spread has on quarterback performance may be the only useful takeaway from this chart. While the trend line for each position rises, it is of a nonsignificant amount (at least to warrant making roster decisions off of) for the remaining positions.

The quarterback line at least crosses the 0-point-spread threshold with a spread range of +5 to -5. We can also see that the confidence interval (the gray-shaded area) of each line widens as fantasy points get higher, signaling less significance in that trend.

Points, Points, Points

Another piece of valuable information that we can leverage is the pre-game point total, which is an expectation of the total points scored.

To be expected, the number of fantasy points scored increases as the projected game total increases. Based on this chart, we can see that the impact of game total on fantasy production is lowest for running backs. The best explanation for this is that games that produce higher point totals often come because of explosive plays, and we see more of those in the passing game than in the rushing game.

As an extension of this, we can get even more granular and examine how players perform compared to their team total:

The trends are very similar, but I would typically prefer using team totals as my first benchmark and then focusing on the game total since one team’s strengths can heavily influence the game total.

For example, a game total of 45 points might feature a team as a 10-point favorite, meaning we would have team totals of 27.5 and 17.5. I would certainly only want to focus on the team with the 27.5-point total!

Player Props

At FantasyPros, we calculate player projections through a wisdom-of-the-crowds approach. But, one source we do not pull in is player prop lines, which can also serve as a different source of projections. Some of these player props are more useful than others, though, especially when you break it down by position.

The few charts use data from the last two years, as historical player prop lines are more sparse:

First, let’s look at passing yards, and it shouldn’t be all that surprising that they are highly variable. As a stat that can range from values of 150 to over 300, a correlation coefficient of 0.43 is actually somewhat encouraging.

As we move on to rushing yards, we find them to be the most predictive of the three stats I cover in this section. Interestingly, the correlation of pre-game rushing yard lines to actual rushing yards is higher for quarterbacks (correlation coefficient of 0.64) than for running backs (0.53). Intuitively, this actually makes sense. The quarterbacks for whom rushing lines are posted – players like Lamar Jackson, Josh Allen and Daniel Jones – have a more secure rushing workload on a weekly basis.

Meanwhile, there is often a subset of running backs that serve as backups in relief roles that could easily be phased out of the game plan should the script play out a certain way.

Finally, as we explore receiving yard lines, a similar trend bears out in that they are not very predictive for running backs. The best part about receiving yards for tight ends and (most) wide receivers is that it is just one of two ways that they will score fantasy points. Receptions can make a bigger difference in Half PPR and PPR leagues, but using receiving yards as a tie-breaker is one of the best ways to leverage Vegas player props.

Unfortunately, the challenge with relying on player props is that not every player always has a prop line posted. Furthermore, not all components of fantasy scoring will be posted. So, while a player may have rushing yards posted, he may not have his receiving yards or receptions posted, which could drastically change his projection. Oftentimes, FantasyPros’ player projections will provide enough detail and information, but you can still leverage Vegas’ player prop odds for more peace of mind.