Coaches Bryan Murray of the Washington Capitals and Keith Magnuson of the Chicago Black Hawks would find life simpler if they could understand why their teams perform like Stanley Cup champions at home and play dreadfully on the road.

Murray at least hopes it stays that way tonight, since his battered club has returned from a pointless three-game road trip to play the Black Hawks at 9.

The Capitals will be trying to set team records of seven home victories in a row and eight straight home games without a loss. That is in contrast to Washington's road record of 2-13-1, worst in the NHL. During existing six-game streaks, wins at home and losses away, not one final score has been closer than three goals.

Chicago is the only NHL team that has lost only one home game. That occurred when Boston visited Chicago Stadium Oct. 14 and the Hawks are unbeaten in 14 home appearances since. Conversely, Chicago has won only twice on the road, where it is 2-8-3.

Some comparative results are ludicrous. The Capitals lost at Toronto, 9-4, then beat the Leafs at Capital Centre six nights later, 11-2. The Hawks thumped Colorado at home, 10-0, and then lost in Denver, 3-2, to the team with the worst home record in the NHL.

Murray thinks the youth of his club is an important factor, with players awed in first visits to such hockey shrines as Maple Leaf Gardens and the Montreal Forum.

Chicago plays on an ice surface that is 12 feet shorter than most and the Hawks try to take advantage of it by coming out fast and skating the opposition off balance. Of course, there is no valid reason for the reverse, the slow way they start out in road games.

The Capitals may be pressing most of the season if they cannot win a couple of games this weekend. Following tonight's contest, they return to New York for a Sunday night game with the Rangers, the team they trail by seven points in the race for fourth place and a Patrick Division playoff berth.

"We come off a road trip like this and now we have to face two tough teams," Murray said. "This is a big weekend. We have to stay within four or five games. Any further back than that and we're going to have an uphill fight with the pressure on us every game the rest of the season."

There will be no reinforcements for a team severely hurt by the loss of its top defenseman, Rick Green, with a shoulder separation. Murray will go with his six right-handed backliners again tonight and he will not change the forward lines that played on Long Island.

Center Harvie Pocza, who sat out that game, was returned to Hershey yesterday. Pocza did not score in two games with Washington.

Alan Hangsleben, paid off by the Capitals last week, has signed a minor-league contract with Hershey . . . Dr. Pat Palumbo, longtime orthopedic surgeon for the Capitals, has been replaced by Dr. Stephen Haas and Dr. Carl MacCartee, who handle the Bullets . . . Goalie Mike Palmateer is in Toronto, where his right knee will be examined by a specialist recommended by Haas and MacCartee.