By STEPHEN WHYNO
AP Hockey Writer
Four teams have opened an NHL season 5-0-0 for the first time in history. Carolina, Florida, St. Louis and Edmonton are off to hot starts. Two-time defending Stanley Cup champion Tampa Bay took two weeks to win a game in regulation. Championship hopefuls Colorado, Vegas and Toronto have struggled early this season. Those sluggish starts are leading to varying degrees of concern. It’s a question of which teams can right the ship before major changes are on the table.