Parity rules the NHL’s Western Conference this season, so teams must strive to maintain their edge from shift to shift and from game to game.

Slippage will be costly, as the Blues learned again during their 2-1 loss to the Los Angeles Kings at home. LA has executed a Blues-like rebuilding plan and now the Kings appear to have a critical mass of young talent.

Jonathan Quick is settling in as the goaltender, continuing the progress he made at the end of last season. Drew Doughty is living up to his billing as the “Next Rob Blake.”

Blues coach Andy Murray shuffled his deck for Game 4 of the season and figures to do more of that in the wake of this loss. He can’t afford to have Patrik Berglund sleepwalking for long, since that compromises this team’s four-line balance.

He can’t sit back and watch his so-called fourth line outplay his other groupings. Guys like Berglund and David Backes (no points in four games) must dig deeper and make a difference.

AROUND THE RINKS: By sending big defenseman Tyson Strachan back to Peoria after Saturday night’s game, was Murray signaling a willingness to give young Alex Pietrangelo a longer look in the days ahead? We’ll see . . . If the Blues aren’t going to give Jonas Junland a look, it will be interesting to see if another team makes inquiries. His fast start at Peoria has been duly noted by scouts tracking the Rivermen this season . . . With the Maple Leafs struggling, how long with mercurial GM Brian Burke wait before making additional moves? He is not known for his patience . . . The Ottawa Sun makes an interesting point about the inflated deal Toronto gave Phil Kessel. Many young forwards, like the ones Chicago has, will be able to use that as a benchmark in coming contract talks . . .  The Bruins rallied to beat the hapless Islanders Saturday night, breaking out of a maddening early-season funk. There is a lot of that going around these days . . . Phoenix hockey fans aren’t quite ready to give up on the Coyotes, who remain in ownership limbo . . . The tireless Spector gets you caught up on all the NHL rumors and speculation worth considering today.