Using Vegas Lines in Daily Fantasy Baseball

Jonathan Bales is the author of Fantasy Baseball for Smart People—a guide designed to help you profit on DraftKings.

There are lots of similarities between each of the daily fantasy sports. Whether you’re playing football, basketball, or baseball, you need to understand basic concepts such as scarcity, consistency, volatility, and opportunity cost. Game theory also plays a major role in tournament success, regardless of the sport.

But then there are elements of game play that are specific to each sport. Throughout the season, you’ll often see me contrast baseball with basketball because I think the two sports require fundamentally different paths to success. Basketball is about value, while baseball is more game-theory-driven, for example. There’s less incentive to go against the grain in basketball due to the night-to-night consistency of many players.

The methods of scoring are also extremely different in each sport. Whereas MLB production basically has no ceiling, there are only so many points to go around in basketball. Fantasy points are scored on every single possession, and the range of possessions in a game is quite narrow. There are only 48 minutes and so many possessions to go around.

Because of that, teammates often cannibalize one another’s fantasy upside. A made shot for one player means no shot attempt for his four teammates on the floor. Stacking in NBA is generally not a smart strategy; if you look at the correlation between any two teammates’ fantasy points, you’ll almost always see it’s negative, i.e. as one goes up, the other declines.

Meanwhile, baseball is all about correlated play; players on the same offense usually perform well in tandem because 1) scoring for one player helps everyone else on his offense and 2) they get to hit off of the same pitcher(s). Thus, stacking teammates is obviously a very advantageous strategy in daily fantasy baseball.

This all adds up to creating value in studying baseball on the macro level. I start my daily fantasy baseball research by looking at entire teams and then projecting down to the individual, not vice versa. I don’t think that’s nearly as valuable in basketball. Yes, it helps to understand which teams are going to do well. But using the Vegas lines as a proxy for individual fantasy production, for example, isn’t as valuable as in other sports.

In baseball, the Vegas lines are king (for me at least). The reason is because, with so much money on the line, Vegas has a clear incentive to make sure their lines are as accurate as possible. And again, the link between team success and individual success—the result of an untimed sport in which teammates’ play is so correlated—means Vegas’ thoughts on how an offense will fare have a direct impact on individual player projections.

The idea that Vegas sets lines solely to balance action is inaccurate; if Vegas purposely set a line that they knew was off, it wouldn’t balance action because sharps would hammer it. The safest way for Vegas to make money long-term is to set accurate lines. If they make accurate lines, they’re guaranteed to make money over the long run.

And the lines are not only accurate, but also a very useful proxy for fantasy baseball production.

Using a total of 8 as a baseline, fantasy production has historically matched up perfectly with the Vegas lines up until a game total of 10 runs. There are a few things that could be going on there, the most likely being that the rare games with a double-digit total have teams with a ton of upside (who also probably hit a lot of dongs), so fantasy production exceeds the Vegas projection. It could also just be the Coors Field effect.

Either way, Vegas is indeed a useful proxy for team fantasy projections. And because individual production is so correlated to the team, you can and should use Vegas as a fundamental component of your daily fantasy baseball research routine.

So how can that be done? Well, stacking an offense with a high run projection is pretty straightforward. I don’t simply look at which offenses are projected the highest and just use those, but I do care a lot about what Vegas thinks if I’m going to stack an entire offense.

You might think, “Well their lines are just intuitive, I know which offenses are best.” To that I respond you should try to predict the Vegas lines for a given slate of games and see how close you come; many times, the actual lines aren’t quite as “intuitive” as you’d think.

Further, even if you could reproduce the Vegas lines, they have a major advantage over you; they’re incredible efficient. In literally minutes, you can gather all sorts of amazing insights that factor in every relevant piece of information: matchup, ballpark, weather, and so on. Why take hours and hours recreating what Vegas is giving you for free?

Finally, note that it’s not just the over/under and moneyline that can be studied. For certain players, Vegas offers a prop regarding their performance on a given day. I find these to be most useful for pitchers, as Vegas offers strikeout props. Because strikeouts are so important for pitchers on DraftKings, you can really aid your pitcher evaluation by taking a glance at Vegas’s strikeout props each day.