Thoughts on CLV

Question

This past week, with Tampa Bay in seeming freefall after four losses in five games, the Bucs and 45-year-old Tom Brady prepared to welcome the first-place Ravens for the Thursday night game. I saw the initial line on the game, Tampa Bay +1.5 points, move immediately to Tampa Bay +2.5 points and, sure that it wouldn’t move on to the key number of +3, I got my Bucs bet down in a hurry.

Not that I knew anything; I never do. As Yogi Berra purportedly said, I don't even suspect anything. Tampa Bay simply fit my bounceback system after losing 21-3 away to a poor Carolina team, and the early money flowing toward Baltimore seemed like the kind of recency-bias-fueled overreaction that my contrarian nature feasts on.

But soon after, the money started flowing the other way, and by the time the game kicked off, Tampa Bay was a solid 2-point favorite. And just like that, I had achieved 4.5 points of closing line value (CLV).

CLV is another of those wagering theories that I don’t subscribe to. The idea is simple enough. The market opens as the bookmaker’s best guess as to how to match action on either side. By the time the market closes, all of the information gathered since the market opened has been baked into the closing line — the closing odds reflect everything known or believed about the game in question. If it has moved in your direction, great: You thought Tampa Bay had value as a 2.5-point underdog, so you made a way better bet than the schmucks who waited to bet Tampa Bay until they were a 2-point favorite.

In this one particular case, all of us schmucks lost — Tampa Bay played about a 30-minute game, led 10-3 at the half, and settled for field goals twice late after having first downs at the Baltimore 13- and 9-yard lines. Tampa Bay failed to get the back-door cover and lost, 27-22.

So, what of CLV? Many people like to brag about being an early adopter, the betting version of “being into these guys before they were popular,” and swear that consistently “beating the market” means more wins over time. Certainly, if getting there early means being on the better side of a key number — getting a team at -2.5 rather than -3.5 — you’ll win a few that you would have lost otherwise, assuming you picked the right side to begin with.

But that’s the rub, isn’t it? People who picked Baltimore at -2.5 were as right as the ones who waited and got them +2. That particular result was a finger in the eye to the people who believe that you’re a hopeless sheep if you make NFL bets “after all the value is gone” (on the day of the game). I’m thinking here of the authors of “The Logic of Sports Betting,” who say in the preface that if you don’t bet NFL games the second the odds are released, “your process is a losing one.”

This is a regular drumbeat in the betting world. The sixth tip in the Washington Post’s “Six tips for becoming a sharper sports bettor” in April 2022: “Focus on closing line value.” Concluded the author, “Over time, you should win a higher rate of bets that have closing line value than those that don’t, which is the point of smarter betting.” Got that? You *should*. No guarantees, though.

As an aside, this followed tip 5, “Place your bets early in the week, not at the last minute.” Why bet early? Well, during the previous season — no, seriously, the tip was based on what the author had observed during one season’s worth of games — opening lines at, say, -2.5 and -6.5 didn’t often get worse, and frequently improved. “It’s a fine strategy to blindly bet any opening or look-ahead line at those numbers,” read the conclusion, “provided the price is -110 or better.”

Bet blindly. I dare you.

As a contrarian, I feel better about a bet when the odds move against me. I get a sick feeling in the pit of my stomach when I realize that what I thought of as brilliance on Monday has become conventional wisdom by the time the game kicks off. No thanks.

garbagetime · Answer