Consider the chorus: “Darling, I don’t know why I go to extremes/Too high or too low, there ain’t no in-betweens.”

The Czechs pulled off the first big upset of the Preliminary Round when they topped Canada 5-4 in a shootout. But just two days later, they were the victims of the next big upset when they dished up a clunker in a 3-0 loss to lowly Germany.

So when Finland faces the Czechs in Thursday’s first quarter-final (14:30) at Malmö Arena, it’ll be hoping that Miroslav Prerost’s squad is in more of a “Germany mood” than a “Canada mood”, so to speak. The Finns haven’t been models of rock-solid consistency themselves.

Following up a 4-1 win over the perennially contending Russians with a 4-3 shootout loss to Switzerland didn’t set the right tone for Karri Kivi’s boys heading into the quarter-finals, even if it was sufficient to secure their second-place finish in Group B.

With that said, the Finns should be favoured to prevail in this matchup. But they’re not taking the Czech Republic for granted.

“I think they’ve got a lot of skill,” said Finnish defenceman Ville Pokka, a three-time World Junior participant. “They skate hard. The most important thing is that we have to improve our game.”

Defence is the biggest strength for the boys in blue and white. Through four games, Finland boasts the tournament’s top penalty kill, clicking at 94.7 percent, with just one goal allowed during 19 opposition man advantages. Starting goalie Juuse Saros has been stellar. Appearing in three games, the Hämeenlinna native’s goals-against average (1.16) and save percentage (95.9) leads all netminders.

If the Finns can get NHL blueliner Rasmus Ristolainen (Buffalo Sabres) and first-line winger Artturi Lehkonen back in their lineup, that would be a huge boost for their medal hopes. The pair has missed the last two games, Ristolainen with a fever and Lehkonen with a leg injury.

While Henrik Haapala has filled in nicely on the top in Lehkonen’s place, potting the winner versus Russia, Lehkonen has great chemistry with captain Teuvo Teräväinen and Saku Mäenalanen. Those two have driven the offense so far, Teräväinen leading the way with seven assists and Mäenalanen recording a team-high four goals.

The Czechs will need a stellar performance out of starting goalie Marek Langhamer to have any hope of advancing. They can’t count on getting the kind of quick start they enjoyed against neighbouring Slovakia, scoring just 18 seconds in during their Preliminary Round-closing 4-1 win.

They need more production from some of their go-to players. Forward Radek Faksa of the OHL’s Kitchener Rangers, appearing in his third World Juniors, is pointless through four games. Highly touted 17-year-old Jakub Vrana, who plays here in Sweden for Linköping of the SHL, has just one goal.

Also important for the Czechs will be avoiding ill-advised emotional outbursts, like defenceman Michal Plutnar's contact with an official during the Canada game, which earned him a one-game suspension.

If the Czechs show up with the same kind of jump and determination as they did against Canada, they have a chance of pulling a minor upset. Otherwise, Finnish fans will be singing for joy as their team moves on to face the winner of Canada-Switzerland in the semi-finals.