The final four are set in the Ontario Hockey League and to no one's surprise those four teams are Windsor, London, Belleville and Brampton. Picked by many as the class of the league, these four teams meet in what will be one of the most heated and unpredictable semi-finals in recent memory. Sportsnet.ca previews both matchups, outlining each team's strengths and the key matchup within the game that could determine the winner of the series.

Western Conference Finals

Windsor Spitfires vs. London Knights

Windsor regular season record: 57-10-0-1 (115 points)

London regular season record: 49-16-1-2 (101 points)

Regular season series: Windsor 5-1

Windsor league championships: One (1988)

London league championships: One (2005)

The Windsor Spitfires' impressive season series win over the London Knights was just the beginning of the heated rivalry that will undoubtedly spill over into this series. The Spitfires won the first five games, only losing the last meeting in a game after they had already clinched first overall in league standings. Windsor staged an impressive comeback win in London on Feb. 6, scoring two late third period goals to win 4-3. London goaltender Trevor Cann will need to step up his play for his team to have a chance against the talented Spitfires.

This series is one many were predicting long before the Knights acquired superstar John Tavares from Oshawa. London rebuilt their team into a contender once again after some key additions in the off-season, particularly defenceman John Carlson from the United States Hockey League and Nazem Kadri in the posthumous Steve Mason trade to Kitchener last season. These two teams met in the opening round in both 2003 and 2004, with London winning both times.

Windsor's potent offence emerged in their victories in the opening two rounds against Owen Sound and Plymouth. Dale Mitchell and Taylor Hall are both averaging two points a game while Andrei Loktionov and defenceman Ryan Ellis aren't far behind. Windsor established themselves as one of the best offensive teams in the league early this season. Their offence is comparable to a snowball rolling down a hill as, once it gets going, it picks up speed and becomes nearly impossible to slow down.

Perhaps one of the biggest reasons behind their offensive success is the play from their back-end. The Windsor defensive core is not afraid to jump in the rush as Ellis and overager Rob Kwiet possess dangerous point-shots on the power-play. Their most glaring weakness is in goal where the team has platooned Andrew Engelage and Josh Unice. Engelage improved in the final three games over Plymouth but will need to be even better against the Knights.

Any team led by John Tavares won't have much difficulty scoring goals. However, two-way forward Phil Varone leads the Knights in playoff scoring with 16 points, one up on Kadri and two more than Tavares. London has a very balanced attack with pint-sized forward Daniel Erlich, Justin Taylor and Philip McRae. Rookie forward Jared Knight also gives London another offensive threat while Zac Rinaldo provides the team another physical, in-your-face type of player.

Carlson and Michael Del Zotto bring London plenty of additional scoring from their defence. Both players often resemble forwards given their penchant for joining the rush. Their timing and vision will give the Windsor defence more difficulty to defend against. Cann performed admirably in the post-season, possibly erasing some doubt about his ability to perform in clutch situations. He hasn't faced a team nearly as strong and deep offensively as Windsor in the playoffs and will need to have a short memory after some disappointing results against Windsor in the regular season.

Key matchup: Ryan Ellis (Wsr) vs. John Tavares (Ldn)

The league's top sniper will likely see plenty of the league's top offensive defenceman. The two were teammates on Canada's world junior gold-medal winning team in January, further adding to their familiarity. Ironically, Ellis outscored Tavares in head-to-head matchups this season with 10 points and a plus-11 rating in six games. Tavares, on the other hand, had nine points and was a minus-3 in those six contests.

Ellis is too often criticized for his defence and size, two aspects of his game that are underrated. A big performance against the league's top sniper will go a long way in helping Ellis shed the label of being a strictly offensive-minded defenceman. Tavares, meanwhile, will need to be instrumental for his team if they're going to knock out the regular season champions.

Eastern Conference Finals

Belleville Bulls vs. Brampton Battalion

Belleville regular season record: 47-17-2-2 (98 points)

Brampton regular season record: 47-19-1-1 (96 points)

Regular season series: Tied 2-2

Belleville league championships: One (1999)

Brampton league championships: None

In spite of meeting just four times over the course of the regular season, the Bulls and Battalion met three times in February, with each game living up to the advanced billing. Like the Spitfires-Knights series on the other side, much of the talk all season was regarding a possible Eastern Conference final versus these two teams. Excluding the first meeting in November, where the Battalion won 7-1, these two teams matched up very well. Both goaltenders were integral parts of their team's success in the season series, a trend that will likely continue in the playoffs.

These two teams have met just once in the playoffs, a six-game series win by Brampton in the opening round of the 2006 playoffs. Brampton then lost to Barrie in the second round, the first of three consecutive playoff losses to the Colts. Belleville's first round loss to Brampton was the last time the Bulls failed to reach the Eastern Conference finals in the last three seasons.

Much like last season, the Bulls found success with a group of talented forwards and a stellar goaltender. Mike Murphy was better this season than he was a year ago, which is impressive considering he was named the league's top goaltender last season. Murphy enjoyed one of the best seasons a goaltender could have, leading the league in goals against average at 2.08 and save percentage at 0.941. No matter how many critics wanted to write him off for his unorthodox style, Murphy is the main reason his team enjoyed as much success as they did.

Belleville made some nice additions shoring up their depth at forward over the course of the season. Their offensive attack is led by American world junior forward Eric Tangradi, who finished among the top 10 scorers this season. Bryan Cameron finished second in team scoring while defenceman P.K. Subban had another huge season in Belleville. The group of Luke Pither, Brandon Mashinter and Nick Palmieri adds size and skill to their group after joining the Bulls in three separate trades.

The Brampton offence is led by world junior star Cody Hodgson, who was a very late cut by the Vancouver Canucks earlier this season. Hodgson is the prototypical captain, the type of player his teammates look up to and try to match his intensity level. He led the team in scoring with 92 points this season but is just as valuable defensively. Rookie of the year winner Evgeny Grachev and Matt Duchene, a potential top five pick in this summer's NHL draft, provide plenty of secondary scoring on the league's second line.

One of the biggest reasons for Battalion playoff failures in previous seasons was a lack of a true No. 1 goaltender. Brampton head coach and general manager Stan Butler made a bold move by trading for Thomas McCollum from Guelph at the trade deadline, a move that has worked to his benefit so far. McCollum is the type of goaltender that can steal games for his team, much like Murphy in Belleville. Butler traded a fairly nice package of youth and picks to Guelph to acquire McCollum - a trade that will largely be evaluated based on his success in this series.

Key matchup: Mike Murphy (Bel) vs. Thomas McCollum (Bra)

Goaltending played a big part in deciding the final three meetings of the regular season and will likely be the deciding factor in the playoffs. Murphy has more experience after coming within a game of winning the league title last year. McCollum, meanwhile, gained valuable experience at the world junior tournament for the Americans but struggled near the end.

Murphy is the rock that steadies the Bulls while McCollum still has a bit left to prove to his team. Brampton acquired McCollum thinking they would need him in a series like this. Unlike the previous two rounds, however, McCollum will be facing more shots against an equal talent opponent which should make his job easier from a mental standpoint. Whichever goaltender is able to steal a game or two should find himself playing in the league championship series.