After his Boston Bruins had defeated the Philadelphia Flyers on Tuesday night, coach Don Cherry produced a copy of the Spectrum program and called attention to a writer's poll of top NHL players in 23 different categories.

"We don't have the best playmaker, we don't have the best stickhandler, we don't have the best penalty killer . . ." Cherry read, right through the 23 listings, where no Bruin was ranked first. Cherry named several Bruins he felt should have been chosen.

A year ago, Cherry bristled when the Bruins became the first Stanley Cup finalists since the St. Louis Blues of the crazy-quilt 1970 playoffs not to place a player on either the first or second all-star team. In truth, the Bruins are not the NHL's second-best team because of the presence of great individual talent, but because of individual efforts on behalf of the team.

Consider defenseman Gary Doak, a 32-year-old journeyman of limited ability whose NHL career began at Detroit in 1965 and has since followed a winding path through Boston, Vancouver, New York (Rangers), Detroit and, since a 1973 trade for Ace Bailey, Boston.

If there were a 24th category, for most often injured, Doak might have given Boston some representation in that writer's poll. Still shaky from a mid-March concussion and fractured cheekbone, Doak sat out the first two games of the semifinal series with Philadelphia. When Brad Park banged up his knee and Dennis O'Brien bent under playoff pressure, Cherry expanded his overworked four-man defense to six by calling on Doak and Al Sims.

Doak played so well in Sunday's 3-1 defeat that he was among the starters Tuesday, and he performed even more capably in a 4-2 Boston success that left the Flyers one game from elimination.

Early in a scoreless contest, Bruin goalie Gerry Cheevers stopped a shot by Bob Kelly and the rebound went directly to Bill Barber in the slot for an open-net score. It would have been a score, that is, except that Doak dove to block Barber's blast with his body.

In the third period, with Boston ahead, 3-1, Cheevers stopped a Bob Dailey breakaway and the rebound wound up on Orest Kindrachuk stick. Again Cheevers had no chance for the save; again Doak made the kamikaze stop.

Many defensemen throw themselves at shots near the point, where they have a good idea of the puck's direction. It takes a special brand of courage to dive into the slot.

"Gary will put his face right in front of a shot to block it," said teammate Terry O'Reilly, who has been known to take some chances himself. "He gives so much he makes us want to give more."

In giving, the 5-foot-11, 190-pound Doak always has found himself taking. His career highlights consist more of medical records than history of achievements.

Twice Doak has broken his right leg, but he admitted with a slight flush that only the second fracture resulted from a hockey accident. The first time he fell roller skating during the offseason.

Sprained knees, sprained ankles and a broken collarbone explain other absences, and he is still shaking the effects of the fractured cheekbone and concussion, suffered when he was bammed from behind into the glass by Detroit Dennis Hextall.

"I guess it beats being on the docks, but hockey can be a hard life," Doak said. "I came to be considered injury prone and I hated it, but there were times when I wondered about it myself. I work hard to get back in shape and the next thing I was hurt again. I think it's just a chance thing. I play hard, but I really don't know why I get hurt so much."

Another problem is the habit of those critical Boston Garden fans who deride players for errors on the ice. Any time a defenseman lets an opponet get past him, he is subject to ridicule, and no defenseman ever plays a perfect game, certainly not Doak.

"The main problem is your confidence," Doak said. "When you come off the bench cold or come back from injuries and are fighting for a job, where is a lot of pressure.

"With the lack of stamina and speed from not having played much, it leads you into holding or tripping penalties when players start to go by you. People don't realize this and they get on guy sometimes. They got on me. You can't say it doesn't bother you. You hear them and it makes you more ense.

"I do the best I can. I'm not going to finesse anybody. I try to stand up and play the body.I work on goals against. If there are no goals in a game when I am on the ice, it is a good feeling."

Doak's chart for the semifinals reads plus one, minus zero, so it is obvious why he is smiling these days. And if the Bruins beat the Flyers in Boston Garden tonight, Doak and his teammates will be smiling all the way to Montreal.