Every team in the National Hockey League could use John Tavares. But as the biggest free agent on the market listens to pitches from potential suitors, the clubs in the mix for his services need him for different reasons.
Whether it's a slim window to win or simply being a No. 1 center away from being a Stanley Cup contender, each team will be dreaming of solving their problems by adding one of the league's truly elite players.
What can Tavares add to the teams vying for his services? Will his presence make them instant favorites? Let's have a look at how he would boost the five teams named as favorites (and a few long shots).
The favorites

New York Islanders
Why they need Tavares: Although the Islanders finished second-to-last in the Metropolitan Division last season, they aren't that far off from being a contender. Led by Tavares, the Isles scored the third-most even-strength goals in the NHL. If they roll out even an average goaltending and defense, Lou Lamoriello's new club could be a scary team, with JT and rising star Mathew Barzal in tow for the foreseeable future.
Where he will impact them the most: Maximizing teammates' skills
Tavares is such an excellent all-around offensive talent that he brings the best out of goal scorers and playmakers alike. When sharing the ice with Tavares, Anders Lee scored 1.40 goals per 60 minutes at even strength (they skated around 700 minutes together, per Corsica Hockey). For context, the league leader among forwards with at least 1,000 minutes (Vegas' William Karlsson) produced 1.38 goals per 60. Josh Bailey had his best career season with 53 assists (all situations), 44 of which came when he shared the ice with Tavares.
Most likely linemates: Anders Lee, Josh Bailey
According to Corsica Hockey, the Tavares-Lee-Bailey line produced 2.75 goals per 60 minutes together, which ranked as the 18th-best line in hockey, just ahead of the Nicklas Backstrom-Alex Ovechkin-Tom Wilson line in Washington.

San Jose Sharks
Why they need Tavares: By signing Evander Kane, the Sharks made it clear they are not going into rebuild mode as their contention window seemed to be closing. Adding Tavares to the mix would provide a shot in the arm to an otherwise aging team that can no longer compete with the West's best.
Where he will impact them the most: Taking pressure off Joe Pavelski (and maybe Joe Thornton)
Last season when facing Pacific Division opponents, Pavelski spent the most ice time against the Sedin twins, Anze Kopitar, Connor McDavid, Derek Stepan and Calgary shutdown center Mikael Backlund. He still performed well, but adding Tavares would allow Peter DeBoer to find some easier matchups for the 33-year-old Pavelski. If Thornton returns, his preferable role at age 39 would be a third-line center with lots of power-play time, rather than handling the No. 1 role.
Most likely linemates: Evander Kane, Timo Meier
Because Logan Couture and Pavelski can effectively play center or wing, the Sharks will have options, but giving a pure goal scorer like Kane a master playmaker could be a terror for opponents. Meanwhile, 2015 first-rounder Meier showed some goal-scoring potential with 21 tallies last season.

Tampa Bay Lightning
Why they need Tavares: Tampa Bay has been on the cusp of winning a Stanley Cup for most of the Steven Stamkos era, but hasn't been able to get over the hump. Since 2010-11, the Lightning have appeared in three Conference finals and reached the Stanley Cup Final once. In 2017-18, they posted the best record in the Eastern Conference, but couldn't finish the job. With an already-stacked lineup, adding Tavares would give Tampa Bay the feel of an NBA superteam.
Where he will impact them the most: Creating an unstoppable second line
When Stamkos and Nikita Kucherov were on the ice together at even strength, the Lightning mauled opponents 53-38 on the scoreboard in 779 minutes. Brayden Point handled the second line admirably last season, but Tavares would give Tampa Bay a Sidney Crosby-Evgeni Malkin effect.
Most likely linemates: Tyler Johnson, Ondrej Palat (with a caveat)
Both players might have to be moved in order to afford Tavares, but if they are still around, Johnson and Palat are the types who can support top-end talents. When Johnson played the majority of his time with Kucherov in 2015-16, Tampa Bay outscored opponents 31-16 when they were on ice together.

Toronto Maple Leafs
Why they need Tavares: The Leafs are in danger of plateauing at a place that isn't quite good enough to win the Stanley Cup. The mere presence of former No. 1 overall pick Auston Matthews should put Toronto in the mix every season, but his supporting cast still has holes, especially with James van Riemsdyk hitting free agency.
Where he will impact them the most: Replacing JVR's power-play production, bumping Nazem Kadri down in the lineup
Mike Babcock never seemed to fully buy in to van Riemsdyk, but the Leafs winger scored 36 goals last season, 11 of which came on the power play. Tavares has reached double-digit goals on the power play three times in his career. As a top-two center, Kadri has had ups and downs. Overall in the last three seasons, the Leafs have been outscored 128-145 with him on ice at even strength. Tavares, on the other hand, has only been outscored at 5-on-5 once since 2011-12 (and by only three goals). If he was pushed to the third line, Kadri would be one of the best players at that spot in the league.
Most likely linemates: Mitch Marner, Patrick Marleau
There may be one dimension to Marleau's game, but that dimension is very impressive. Last year, Babcock routinely used Kadri between Marleau and the team's young leading scorer, Marner. Putting Tavares between them would create a rich man's version of Bailey and Lee, with one gifted playmaker and a pure goal scorer.

Dallas Stars
Why they need Tavares: A strong season from summer acquisition Alexander Radulov and a desperate coaching change weren't enough to get the Stars back in the mix last season. GM Jim Nill's team is running out of time to win while his top wingers Radulov and Jamie Benn are in their primes.
Where he will impact them the most: Giving them a better version of 2015-16 Jason Spezza
Dallas continued the trend of the Tyler Seguin era of being a top-heavy team. With Seguin, Radulov and Benn on the ice, they outscored opponents 38-22 and posted an outstanding 52.9 Corsi for percentage. With Benn off the ice, the Stars' goal production sunk by 1.46 goals per 60 minutes. One line is simply not enough. In 2015-16, Spezza scored 33 goals and added 30 assists, giving the Stars a dangerous second wave. Dallas reached the second round of the playoffs, with Spezza elevating the play of Mattias Janmark and Valeri Nichushkin. Since Spezza's play has dipped, the Stars have had a huge hole that Tavares could fill.
Most likely linemates: Alexander Radulov, Valeri Nichushkin
With news of Nichushkin returning from the KHL, the Stars will want to give the 2013 first-round pick every chance to maximize his terrific offensive gifts. While Radulov was excellent on the Seguin-Benn line, he could balance out some of Nichushkin's defensive shortcomings.
The long shots

Nashville Predators
Why they need Tavares: The Predators added two proven centers, Kyle Turris and Nick Bonino, to the mix for 2017-18, strengthening their forward group and creating a more flexible lineup. It still wasn't quite enough to get past the stacked Winnipeg Jets. Nashville's offensive attack was solid during the regular season, ranking eighth in even-strength goals, but with support from an outstanding blue line, Tavares could push the Predators up toward the top on both sides of the ice. Without Tavares, the Preds will enter next season as a strong contender. With him, they would be considered the most dangerous team in the NHL heading into 2018-19.

Boston Bruins
Why they need Tavares: Boston's window was held open by a few young guns -- especially defenseman Charlie McAvoy -- who stepped up and provided the B's with the top-pair blueliner and depth scoring they had been missing. Still, Boston was a contender largely because of the dominance of Patrice Bergeron and Brad Marchand. With the two superstars in their 30s, there are only so many years left to raise another Cup in Beantown. If he signed with Boston, Tavares would push the Bruins to a level past Tampa Bay as the most stacked team in the Atlantic.

Vegas Golden Knights
Why they need Tavares: With a trip to the Stanley Cup Final in the franchise's inaugural season, the expectations for Vegas are now sky high for their sophomore season. The problem: James Neal and David Perron are leaving for free agency, and top scorer William Karlsson is likely to drift back to the pack following a 43-goal season bolstered by an unsustainable shooting percentage. With the league chasing Vegas in 2018-19, Tavares would take pressure off the young playmakers looking to replicate their magical season, and he would make up for production lost to free agency.