According to OddsShark, the Leafs and Tampa Bay Lightning are both listed as 15-2 (+750) favorites:
The third choice is the Winnipeg Jets at 19-2 (+950), making them the team with the best odds to win the Cup out of the Western Conference.
Last season's Stanley Cup finalists, the Washington Capitals and Vegas Golden Knights, are both listed at 11-1 (+1,100) along with the Nashville Predators, who were Cup finalists in 2017.
Close behind them at 12-1 (+1,200) are the Boston Bruins and the Pittsburgh Penguins, who won the Stanley Cup in both 2016 and 2017.
The Leafs have reached the playoffs in each of the past two seasons only to get eliminated in the first round. With Tavares joining a forward group that includes Auston Matthews, Mitchell Marner and William Nylander, though, they figure to be a tough out in 2018-19.
After signing Tavares on July 1, OddsShark showed bookmakers had the Leafs as the sole Stanley Cup favorites at 6-1 ahead of Nashville at 9-1 and both Tampa and Winnipeg at 10-1.
The Lightning haven't made any major moves since then, but they have managed to close the gap because of their deep and talented roster.
Tampa Bay has reached the Eastern Conference Final or better in three of the past four seasons, and it has top-end players at every level.
Forwards Nikita Kucherov and Steven Stamkos, defenseman Victor Hedman and goalie Andrei Vasilevskiy are all in the conversation as the best players at their respective positions.
Additionally, Tampa has been a rumored destination for two-time Norris Trophy-winning defenseman Erik Karlsson since July.
No movement has occurred on that front, but Karlsson could be precisely what Tampa needs to get over the hump and win the Stanley Cup.
Even without him, the argument can still be made that the Lightning have a better all-around team from top to bottom despite the Leafs' addition of Tavares.