A little monster sit on Max McNab's desk. The monster has a green face and its name is Sammy Slam-Me, The frustration Reliever. It is the perfect Christmas gift for a man who is the general manager of the Washington Capitals, a hockey team of small distinction and mighty frustration.

By bringing one's fist down on Sammy's little green head, one drives a metal ball up a chute, a la the strong-man's test at a carnival. If one's frustration produces enough steam, the rising ball rings a bell at the top level marked: "VIOLENT RAGE."

Sammy's presence is evidence the Caps can still smile. The front-office people exchanged names for Christmas gifts."Whoever got mine," McNab said, punching Sammy, "must have heard me ranting and raving."

It was a little joke on himself, that allusion to raves and rants, but McNab, more than anyone, knows the Caps' dilemman is not funny. They have better players than ever. They have more of them. Yet, maddeningly, the Caps are in trouble. People are staying away from games. People are booing everything except the puck. And the Caps' won-lost record is still one of the three worst in the National Hockey League.

In their fifth year, the Caps now have taken a second step backward. Last season they suffered a series of injuries that destroyed the club's talent and will. The Caps won 17 games, down seven from the year before; a disaster.

But then, for reasons that can not be explained, the Caps' owner, Abe Pollin, and McNab decided to fire the coach, Tommy McVie. They did it the day before this season was to start. The argument here is not over the firing of McVie; perhaps the man who was runner-up in coach of the year coting in 1976 had grown stupid. But what sense does it make to fire a coach the day before the season starts?

McVie had chosen the players and trained them in a system. He was fired and replaced by a minor league coach who would have to spend a season trying to learn things about the Caps that McVie knew as well as he knew his children's names.

The best you can say of the McVie firing is also the worst you can say of it: Pollin and McNab needed to make a move to convince Capital customers they are trying to do the right things. That is not doubted. But the move was wrong for every reason it can be wrong. The price of that mistake is confusion that has rendered the Caps immobile.

The new coach, Danny Belise, has an impossible joh. He has to teach his system, evaluate players, judge character-and do it under the gun of NHL competition in an arena half full of fans angry at an organization that after five year in business still does foolish things such as fire the best coach they ever had.

Even 30 games into the season, confusion clings to the Caps so tightly that, in the first period against the Flyers last Tuesday night, the Caps twice were penalized for having too many men to the ice. The penalty is called on a good team maybe 10 times a season.

It happened to the Caps because they are searching for the right lineups. Players are being shuffled on and off so many lines, in and out of so many position, that moments of confusion are inevitable. And those moments can be costly in NHL.

They are especially costly when a team's level of talent is beneath the rest of the league's, anyway. Without wingers, who can score, a hockey team is crippled. Bob Sirois and Tommy Rowe are the only Cap wingers whose statistics are improved from last season. Four other wingers are new, and none is getting much done. A respectable NHL team has four good wingers; the Caps have perhaps two.

Five centers are too many because they can not get enought playing time and they take up roster spots better saved for more versatile players. Three centers is ideal. The Caps have five (not because they particularly want five, but and expansion team takes the best players it can get, whatever position they play).

Belisle is using three pairs of defensemen. Montreal, say, would use two pairs, keeping back a fifth roster spot for a power-play specialist or an "enforcer" type. Belisle is forced to carry six defensemen because he is looking for four who can do the job.

So the Caps could use a Guy Lafleur on the wing. Bryan Trottier at center would make the Caps' wingers 40-goal scorers. Put Ken Dryden in goal and the Caps move up four or five notches in class immediately.

If to no avail, the Caps yet have given their customers an honest effort. They have tried everything (five coaches, two general managers, 37 wingers and nine goalies in five seasons) and they have kept their important promise of not trading away draft choices for immediate but temporary help.

The Caps ask patience. Defenseman Rick Green, an exceptional athlete playing uninjured for the first full season, said, "We're a young team and we're coming together now. I just hope the fans hang in there with us. It will be a great time."

The fans are not hanging in there sweetly. Attendance is down almost 3,000 a game. The 8,000 who show up are angry. They began booing during pregame introductions last week. With seven seconds to go in a 4-4 tie, Green and fellow defenseman Pete Scamurra skated onto the ice.

The fans booed them mightily.