NHL Playoff Betting Tip: How to Approach Game 7 Over/Unders

Tuesday’s pair of Game 7s were high-scoring affairs. The Boston Bruins found the back of the net twice in the first period and cruised to a 5-1 victory over the Toronto Maple Leafs.

In one of the wildest Game 7s you’ll ever see, the San Jose Sharks rallied from a 3-0 third-period deficit to beat the Vegas Golden Knights, 5-4, in overtime.

The Bruins-Leafs over/under was 5.5 while the Sharks-Knights total closed at 6. The over hit in both games.

After watching Tuesday’s shootouts, a majority of tickets are on the over 5.5 in Game 7 between the Washington Capitals and Carolina Hurricanes (7:30 p.m. ET, NBCSN).

However, both of last night's overs were unlikely to hit. According to The Action Network win probability, the Bruins-Leafs under had an 85% chance of cashing with one minute remaining. The Bruins scored with one second left to push the game over and there was confusion whether the buzzer-beating score was going to count.

There was nearly a 90% chance the under would hit with the Knights leading 3-0 in the third. It took a controversial five-minute major in which the Sharks scored four goals for the under to lose. Over bettors got lucky.

Recency bias has gamblers believing the over is the smart bet tonight but history suggests the under is the sharp side.

Sample size is a problem when trying to find Game 7 trends. That’s why I included all games in the Bet Labs database, as well as Game 7s dating back to 1996 that had betting lines. This gives us an 88-game sample. It’s not huge but it nearly doubles the results in our database.

Playing a seven-game series in the Stanley Cup playoffs can be exhausting. The theory is that players become fatigued and increased familiarity with an opponent — players and coaches make adjustments — lead to low-scoring games.

Does the data support this idea?

Since 1996, the under is 42-33-13 (56.0%) in Game 7s.

The under becomes more profitable in higher total games. In Game 7s with an over/under of 5 goals or more, the under is 36-25-13 (59.0%) since 1996. If the total is 5.5 or greater, the under has gone 13-7-1 (65.0%) over the same span.

More than 60% of tickets are on the over 5.5, but a majority of dollars are on the under, which means larger bets, often from professionals, have been placed on the under.

Casual gamblers will be cheering for goals, but the sharps and history are with under bettors in Game 7.