A good sports betting column should be backed by a profitable gambler with a proven track record. It should offer picks generated by a sophisticated and conceptually sound model. Most importantly, it should treat the subject with the seriousness it warrants.
This is not that column.
Instead, this will be an offbeat look at the sports betting industry—why Vegas keeps winning, why gambling advice is almost certainly not worth the money, and the structural reasons why even if a bettor were profitable, anything they wrote would be unlikely to make their readers net profitable, too.
While we're at it, we'll discuss ways to minimize Vegas' edge and make recreational betting more fun, explain how to gain an advantage in your office pick pools, preview games through an offbeat lens (with picks guaranteed to be no worse than chance), and touch on various other Odds and Ends along the way.
How to Spot a Sharp Bettor
This offseason, I built a new model to help make my picks. Through five weeks, that model has gone 10-4-1; if every bet was made at (-110) odds, that would work out to a 33.9% average profit. It has posted a winning record in every week.
This has me thinking about how we tell whether someone has an edge. Most assume it's just a matter of looking at their profit—by that measure, surely my model is sharp. And yes, over a large enough sample, the only viable measure of whether a bettor has an edge is whether they turn a profit.
But that "over a large enough sample" bit is doing an awwwwwwful lot of work there. As we discussed earlier this season, randomness is far streakier than most people would expect, which means "square" betting strategies are going to have a lot of windows where they're fairly profitable. As evidence, I present... my model this season. (I assure you, it's as square as they come.)
There is a less-noisy way to separate the bettors with an edge from the donors: Closing Line Value, or CLV.
What is CLV?
At the time I'm writing this, the Ravens are favored by 5.5 points over the Browns, but that line is subject to change. If Zay Flowers injures his hamstring in practice, the line will move toward the Browns. If an unexpected storm moves in on Cleveland, the line might shift further toward the Ravens (since they have a stronger running game), or it might shift in favor of the Browns (because bad weather produces low-scoring games, and those tend to be closer simply because there are fewer points to go around).
This is all fairly obvious. Lines move all the time. This is why the section devoted to this week's lines is called "Lines I'm Seeing"; implicit in that is the idea that the lines you see will likely be different.
If I bought the Ravens at -5.5 and the line moved to Baltimore -6.5, I'm essentially getting an extra point for "free". I will win my bet if the Ravens win by exactly 6, while anyone who bought the later line will lose. On the other hand, if the line moved to Baltimore -4.5, I have "overpaid" for my bet; my bet will lose on a 5-point Ravens victory, while if I'd waited before buying, that score would have won for me. This is Closing Line Value, the amount of "free" points you get on your bets.
At any given moment, though, the line represents all information currently known to Vegas. To a square bettor like me, the direction the line will move is essentially random. From my perspective, it is just as likely to move in the direction of the Browns as the Ravens. As a result, that line movement should work in my favor about half the time and against me about half the time. In the long run, my expected CLV is 0.
But imagine I had inside information on the Ravens. Or that I was able to better predict the weather this weekend. Or that I was able to consistently align myself with the other sharp bettors. You'd find the closing lines moving in a direction favorable to me far more often than they were moving against me, and I'd accumulate a significant amount of CLV.
This CLV is one of the best statistical predictors of long-term profit, and it's far less noisy than short-term results.
Vegas is Watching It (Even If You Aren't)
The problem with CLV is that Vegas understands its importance and tracks it much more closely than we do. Vegas doesn't care that my model is 10-4-1 so far this season; they have already reverse-engineered my full model (despite my repeated exhortations not to—rude) and it doesn't scare them in the slightest. They're happy to accept as much action as I want to give them.
But if I was averaging 1 point of CLV per pick? They'd cap my bets or cut me off in a heartbeat. They are not obligated to take anyone's action, and if they're convinced you have an edge over them, they'll freeze you out. Yet another way the game is rigged in their favor.
So what use is CLV to us? Well, if you're following a tout and want to see if they have any real juice, you can take a page from Vegas and track their CLV over time. If you're blinded by my current record, you can track CLV for my model; you'll quickly discover that I'm every bit as square as I keep assuring you I am.
Additionally, if you are in any pick pools, those usually lock the lines at a specific time so everyone is picking against the same spread. In that case, you can just wait until right before kickoff to make your picks and bank all that free line movement for some serious guaranteed CLV. It's the easiest way to see what life is like for a sharp bettor.