They played in different eras, Gordie Howe when the game was more tightly checked, Bobby Orr as the NHL expanded and the style of play changed, and Wayne Gretzky when the approach was wide open.

Each possessed singular abilities and produced remarkable results.

But who was “the greatest” — Howe, Orr or Gretzky?

Families at dinner tables, friends at bar rails and fans in stadiums will debate it until a fourth name is added to the question — or the game is no longer played.

Howe was an icon of the World War II generation. Powerful and big, especially for his era, used the threat of violence to create playing space, so Sid Abel and Alex Delvecchio, brilliant playmakers, readily could pass the puck to him and Howe could deftly maneuver.

Shooting from either side with equal aplomb, including back-handed with the straight-blade sticks of the era, the puck often arrived hot and accurately propelled by Howe’s seemingly unparalleled strength.

Orr arrived at 18, five years before Howe retired from the Red Wings. A darling of the baby-boom generation, he revolutionized the game — and no one has quite played it like him since.

A defenseman, he produced points at a rate equal to the best scoring forwards of his era.

His approach took the historic styles of playmaking, offensive defensemen like Eddie Shore, Doug Harvey and Pierre Pilote to dimensions so elevated and pioneering that purists objected.

Who did this 18-year-old fresh-faced kid with a crew cut think he was, a fourth forward?

His rushes were magnificent. His playmaking, unparalleled at his position and among the several best NHL forwards, was nothing short of revolutionary.

As for “getting back” on defense? Orr skated like the wind.

Orr did help drive a transition to a more free-flowing, unbridled style of offense. But no one has appeared since who combined Orr’s unique array of skills.

Gretzky arrived the year after Orr retired, and saw the game with new, gifted eyes. Participants and observers assert he was more perceptive than anyone who played.

His goal-scoring skills largely were unrivaled, even with turbo-charged offensive play dominating the league. But Gretzky’s playmaking ability was even greater. The incomparable talents were well-coordinated. Such was his adroit improvisation that comparisons to the genius of jazz musicians are entirely apt.

Scrawny in a physical game, opponents thought they could neutralize him with constant pounding. But Gretzky’s creativity, wisdom and skating transcended them.

Each player’s dossier is replete with greatness. Many observers say any comparison is ultimately futile because of the vastly different era in which Howe, in particular, played.

But the fact of the matter is, Orr and Gretzky assert publicly Howe is “the greatest.”

Gordie Howe

■He won four Stanley Cups, six Hart Trophies as MVP and six Ross Trophies as leading scorer.

■He surpassed Maurice Richard’s NHL goal-scoring record of 544, and went on to score almost 50 percent (257) more, plus 174 in the World Hockey Association.

■He garnered 1,049 assists in the NHL, 334 more in the WHA.

■An NHL All-Star 23 times, his records for games and seasons played still stand.

■He ranked among the top 10 in scoring 21 consecutive seasons, and his 95 points in 1952-53 was a record.

■In 157 playoff games, he tallied 160 points (68-92).

His prolific offense occurred in a far-more defensive era. The red line at center ice was introduced three seasons before the 19-year-old arrived in Detroit as an initiative to expedite the proceedings. Passing out of the defensive zone had been prohibited.

It all took some time to sink in.

Howe also shot only against five of the six best goaltenders in all of Canada, and a highly exclusive club of players on rosters that expanded from only 15 to 18 across the course of his career, assuring a continuously high level of play.

At the start of Howe’s career, the average tally was 4.8 goals per game. By the end, it was 8.0.

Meanwhile, his defensive abilities and dedication to the task were stellar.

Bobby Orr

■The only defenseman ever to win the scoring title, Orr did it twice.

■He won two Stanley Cups, eight consecutive Norris Trophies as best defenseman and three consecutive Harts as MVP.

■He was the first defenseman to score 30 goals. Then, he scored 40.

■He was the first player at any position to garner 100 assists.

■In 1970-71, Orr scored 37 goals and added 102 assists. He was a plus-124 for the season, an NHL record.

Despite the outsized performance, observers say Orr played when the NHL — in a huge mistake, in the minds of many — expanded from six to 12 teams in one season. Long before the huge influx of Europeans and well before the lifting of the Iron Curtain, many rosters resembled their AHL counterparts for several seasons.

He also played during the introduction of curved sticks, which remarkably enhanced players’ ability to control and fire the puck, leaving goaltenders scrambling for both masks and new techniques to cope.

But Orr’s greatness was such that the detractions seem mere quibbles.

Wayne Gretzky

■Such was “The Great One’s” offensive prowess that he has more assists than any other NHL player has points.

■He won four Stanley Cups, nine Hart trophies, as MVP, and 10 Ross trophies as scoring champ.

■The leading scorer in NHL history, he is the only player to tally 200 points or more in a season. Gretzky did it four times.

■He scored more than 100 in 13 straight seasons, and in 16 of the 20 he played.

■At the time of his retirement, Gretzky held 61 NHL records, including career goals (894), assists (1,963) and points (2,857).

■In 1981-82, he scored 92 goals in an 80-game season.

■In 1985-86 he assisted on 163 goals, in an 80-game season, on his way to tallying a record 215 points.

Gretzky played at a time when games were high-flying, often comparatively defenseless affairs. If he was possessed of much in the way of defensive skills, it was unusual to have to brandish them.

Just several years later, with the advent of more systematic defenses emphasizing, in effect, zone play, scoring declined.

Gretzky would have excelled regardless, and his performance likely would have been similar, but the statistics are not quite so gaudy.