World Juniors history: There's not much at the top level. The best finish for Belarus, which made its debut at the top level of U-20 competition in 1998, was ninth place in 2001 and 2002. They enter this tournament after winning gold in the 2017 Division I tournament to earn a promotion. At that tournament, they won four of their five games with their only loss via a shootout to Germany.
Coach: Yuri Faykov
Key players: Defenseman Vladislav Yeryomenko is having a strong season for the Calgary Hitmen of the WHL with 25 points (seven goals, 18 assists) in 30 games. He played for the U-20 team last year at the World Junior Division I tournament, scoring one goal with two assists in five games.
Also returning is defender Vladislav Martynyuk who had a goal and three assists for Belarus last year.
Forward Yegor Sharangovich has the most experience, playing in his third (and last at age 19) World Juniors. He was the only player on the team's preliminary roster to be playing pro hockey this year, with four goals and six assists for Dinamo Minsk in the Russian KHL.
What to expect: Belarus finished last in 2016, knocking them down to Division I last year. But they were impressive, and dominating, at the Division I tournament in 2017, outscoring opponents 20-10 over five games. Not likely to medal, but watch for a scrappy team which doesn't want to suffer relegation again.
Team Czech Republic
World Juniors history: Won its two gold medals back to back in 2000 and 2001. Last medaled in 2005 when it won bronze. Last year, finished third in Group A but lost to Canada, 5-3, in the quarterfinal and finished sixth overall.
Coach: Filip Pesan
Key players: Buffalo Sabres fans will keep their eyes on the blue line watching prospect Vojtech Budik. Budik was a fifth-round draft pick of the Sabres in 2016. He was on the Czech Republic's 2017 World Junior team, but only played two games. This season he has two goals and nine assists in 31 games with the Prince Albert Raiders of the WHL.
Also returning is Ondrej Vala who has seven goals and 12 assists in 30 games for the Kamloops Blazers. Vala signed a three-year entry level contract with the Dallas Stars in September 2016.
Goaltending duties will likely fall to Jakub Skarek who started three of the Czech Republic's five games in last year's World Juniors tournament, including a win over Finland, an overtime loss to Switzerland and the quarterfinal loss to Canada. Skarek is playing in the Czech Elite League.
Vying for time in the net will be Josef Korenar, who was signed to an entry-level contract by the San Jose Sharks in July. In the 2016-17 season he played junior hockey in the USHL posting 14 wins with a 2.22 goals-against average and a .925 save percentage for the Lincoln Stars. This season, he has returned home to play in the Czech Republic's second league.
What to expect: The Czech Republic looks to be more of the same from recent history – a solid middle-of-the pack team that lacks an elite talent to make a serious medal push.
World Juniors history: The last time Russia won gold at this tournament was the last time it was in Buffalo, back in 2011 when they were in a 3-0 hole to Canada but roared back with five goals to win the tournament. Russia has won a medal in the last seven world junior tournaments including the bronze last year. Overall Russia has four goals, nine silvers and eight bronze for an overall medal count of 21, second only to Canada's 30 medals.
Coach: Valeri Bragin
Key players: The star, assuming he's healthy, will be Andrei Svechnikov. The 17-year-old right winger is projected as the No. 2 overall pick in this summer's NHL Entry draft. He returned to the Barrie Colts lineup Dec. 8 after missing seven weeks with a hand injury. It only seemed to take him one game to get his groove back as he had two assists in his second game and notched his first goal back in his third game. He has 17 points (11 goals, six assists) in 13 games in the Ontario Hockey League this season.
Also look for forward Klim Kostin who was selected by the St. Louis Blues in the first round of the 2017 raft. Kostin has been playing for the Blues' AHL affiliate, the San Antonio Rampage. In 24 games he has two goals and nine assists. Kostin has plenty of international experience, captaining Russia's U17 and U18 team in the 2015-16 season, winning a silver medal with the U17 team.
Forward German Rubtsov suffered a concussion at last year's tournament. Rubstov is playing his second season in the Quebec Major Junior Hockey League. He began the year with Chicoutimi then was traded to Acadie-Bathurst. Combined this season he has seven goals and 17 assists in 23 games.
What to expect: A repeat of 2011 is unlikely but never quite count the Russians out of the medal round. Look for a push into the medal round where anything is then possible.
World Juniors history: Sweden has won 17 medals including two goals, 10 silver and five bronze but hasn't won a medal since falling to Finland in the 2014 title game. Last year, Sweden finished tops in Group A but lost, 5-2, to Canada in the semifinals, then lost to Russia, 2-1 in overtime, in the bronze medal game.
Coach: Tomas Monten
Key players: All eyes will be on defenseman Rasmus Dahlin, the projected No. 1 overall pick in the 2018 NHL Entry Draft. The two-way player has five goals and six assists in 26 games playing for Frolunda HC in the Swedish Hockey League.
But he's not the only player to watch on Team Sweden. Elias Pettersson, who was Vancouver's first-round pick at No. 5 in the 2017 draft, has 35 points in 26 games in the Swedish Hockey League, making him one of the key forwards.
Marcus Davidsson was a second-round pick of the Buffalo Sabres in 2017. Playing for Djurgardens IF in the Swedish Hockey League, he has two goals and seven assists in 23 games.
Meanwhile the blue line is deep for Sweden. So deep that Adam Boqvist, a player projected to be a top-10 draft pick in June, didn't make the preliminary roster. The defense features Timothy Liljegren and Erik Brannstrom, both first-round picks in 2017. Liljegren, who was selected 17th by the Toronto Maple Leafs, has one goal and eight assists for the Marlies in the AHL this season. Brannstrom, selected 15th by the Vegas Golden Knights, has six assists in 27 games playing for HV71 in the Swedish Hockey League.
What to expect: Sweden has lost in the bronze medal game for the past three years. With a solid roster, look for Sweden to again be at the top of pool play with an aggressive push to turn that into a medal.
World Juniors history: The Swiss have medaled just once in this event, a bronze in 1998. Last year, Switzerland advanced to the quarterfinals losing, 3-2, to the United States and finished seventh overall.
Coach: Christian Wohlwend
Key players: Defenseman Tobias Geisser was drafted in the fourth round (120th overall) by the Washington Capitals in 2017. A two-way player with a hard shot, he has one goal and three assists in 24 games for EV Zug, a team in the top-tier Swiss league. Geisser's size makes him a dangerous player as well, listed at 6-4, 201 pounds.
Also on the blue line is Nico Gross, who one goal with one assist for the Swiss junior team last year. Draft eligible this summer, he has three goals and five assists with the Oshawa Generals of the OHL this season.
Among the forwards, watch for Gilian Kohler and Philipp Kurashev. Kohler has three goals and five assists for the Kootenay Ice of the WHL. Kurashev has eight goals and 23 assists for the Quebec Remparts of the QMJHL. Both are draft eligible this summer but only Kurashev was on the NHL Central Scouting "Players to Watch" List, projected as second or third round selection.
Gross was also on Central Scouting's list, projected as a late-round pick.
What to expect: Medals are hard to come by for Switzerland and there's no expectations for one this year. Unlikely to go deep in the tournament, the Swiss will still be fun to watch.