Zig Zag Theory

The zig-zag theory is one of the most popular mainstream sports betting strategies, particularly when it comes to sports that utilize series-based playoff games. This most notably includes the NBA and NHL, though variations of the zig-zag theory can be applied to the NFL and MLB to a lesser extent.

In this article, we’re going to cover some of the finer nuances of the zig-zag theory (and remember, it’s just a theory, no bet is ever guaranteed), as well as some things we can learn from it overall. The zig-zag theory primarily applies to single game outcome betting (Moneyline), but according to a Betting.com guide, you should do diligent research on how the betting site you use actually interprets the Moneyline.

How does the zig-zag theory work?

It’s really quite simple, the idea is that you just bet on the team that lost their last game. This might sound peculiar, but it’s believed that a team coming off a loss will be motivated to perform harder in the next game.

Immediately, you might imagine some flaws in this theory. For starters, it’s the equivalent of guessing “heads” every time a coin lands “tails”, right? But how do you account for “tails” coming up multiple times in a row? Or in the case of sports teams, a losing streak?

Does the zig-zag theory have any merit?

To a degree – there is some evidence that the zig-zag theory had merit behind it, based on point spread results of NBA playoff zig-zags between 1991 to 2014:

  • Overall: 786-693-37 • 53.1 percent
  • Game 2: 195-153-13 • 54.7 percent
  • Game 3: 195-159-6 • 55.1 percent
  • Game 4: 159-163-8 • 49.4 percent
  • Game 5: 128-121-6 • 51.4 percent
  • Game 6: 79-70-2 • 53.0 percent
  • Game 7: 30-27-2 • 52.6 percent

So while you can immediately equate the zig-zag theory with coin tosses, it becomes apparent that zig-zags had peak odds in game 3, before spiking down. The best odds seem to come from double-digit underdogs that are coming off either an SU (Straight Up) or ATS (Against the Spread) losses – at least in the NBA.

But wait, why am I using past tense verbs (“had merit”)?

Until 2013, the NBA used a 2-3-2 format, but switched it to a 2-2-1-1-1 format after 2014. A 2-2-1-1-1 sees the home advantage for the higher seed on the first two games, then the next two being away, before one home, one away, and the final match is at home.

In the NBA, it’s statistically proven that teams typically wins over 60% of games in their home court, due to a number of factors. The factors don’t really matter for our point (home crowd cheers, referee bias, etc), what matters is how these statistics relate to the zig-zag theory.

All right, so let’s use the Chicago Bulls and the LA Lakers as our examples. Games 1 and 2 are in the Bulls court. Games 3 and 4 are in the Lakers. Then it goes Bulls, Lakers, Bulls, right? So strictly speaking, based on “home court advantage”, the Bulls would be favoured to win games 1, 2, 5, and 7. On paper.

But let’s say the Bulls actually lose game 1, even with the home court advantage. The zig-zag theory now says that the Bulls have a >76% chance of winning game 2, because we’re combining the home court advantage with the zig-zag theory.

Now we get to game three. If the Bulls won the first 2 games, then the Lakers would be expected to win due to now having the home court advantage, and the zig-zag theory on top of it. But even if the Bulls lost game 2, the Lakers might still be expected to win game 3 because the home turf theory now applies to them (at some point, this should all be renamed into the “home turf zig-zag theory”).

And now some of you mathematicians may be doing mental acrobats. “The Bulls had a >60% chance of winning game 1 and 2, but lost game 1, so then they had a >76% chance of winning game 2, so that means the Lakers have a >76% chance of winning game 3 if they lost game 2, because home turf and zig-zag, and if the Lakers lose game 3…”. Stop, I can see the smoke coming out of your ears. Remember that this is all just theory.

At the end of the day, the zig-zag theory really allows you to just not bet against the road team for every game, no matter what the odds suggest.

What have we learned?

As you can see, the zig-zag theory relies on 1) the home court advantage, and 2) the idea that a team will be more motivated to win after a loss. It’s a fun way to predict winners and place your bets, but ultimately, it’s not a bulletproof theory – hence why it’s just a theory.

If you look at the 2016-17 NBA season, the zig-zag theory was absolutely riddled full of holes. Teams off an SU loss went 21-42-1, which would’ve given you about a -0.3% ROI if you consistently used the zig-zag theory as a betting guideline.

Ultimately, the best sports betting practice is to actually do your homework. Really drill down into individual player stats, past betting spreads, pay close attention to injury reports, etc. These will help you more than zig-zagging your bets. However, there is certainly merit to the home court advantage, so don’t toss the zig-zag theory completely out the window.