Just 15 games into the National Hockey League season, a coaching termination: Tom Watt fired at Winnipeg, with Jets General Manager John Ferguson taking over as interim coach.

With Smythe Division cellar occupancy, never mind that the Jets are the league's youngest team, or that just two seasons ago first-year coach Watt won the Jack Adams Award as the NHL coach judged to have contributed most to his team's success (a record 48-point jump, from 9-57-14 under Tom McVie et al. to 33-33-14). Ferguson declared at a hastily assembled news conference yesterday, "Tom Watt and I are not on the same wavelength.

"The bottom line is we're 4-9-2 . . . We're a better hockey club than that."

Ferguson, a rough, tough player, likes his players that way; Watt leaned to disciplined, speedy European-type skaters . . .

It's tough all over the NHL. The league has declared Denis Potvin's consecutive-game assist streak over although he has an assist in all 12 games he's played this season. Thing is, the Islanders have played 13; he missed one with an allergic reaction and "all records pertain to a continuous streak of games."