Carping at surprise best picture contenders is a favorite indoor sport among many Oscar mavens. (Confidently handicapping the field and getting picks wrong is their second favorite.)

Some controversies have legs that lasted decades. 1968 outrage over the muscled-out “2001: A Space Odyssey” may even be greater now that the Kubrick epic’s legendary status is sealed. Jaws still drop to discover “North by Northwest” was edged out by “The Nun’s Story” and “African Queen” was pushed aside for “Quo Vadis.”

“Huh?” moments — as in, “They named ‘Ivanhoe’ instead of ‘Singin’ in the Rain?’ ” — are legion, although that bizarre turn of events in 1952, when Robert Taylor’s medieval muddle knocked out Gene Kelly’s timeless tuner, remains a low-water mark for many veteran Oscar watchers.

For instance, fluff like 1935’s “Naughty Marietta” routinely contended with enduring classics. When “Three Smart Girls” (1936) is given a shot at the top trophy, no nominee is likely to be particularly startling, though eyebrows doubtless went up whenever a film was put up for best picture but nothing else, like “Libeled Lady” (1936) or “The Ox-Bow Incident” (1943).

Movies and awards both got serious once WWII wound down and Europe became a recognized source of quality. Columnist Hedda Hopper went ballistic when such British efforts as “Great Expectations” (1947) and “The Red Shoes” (1948) made it into the lineup. “Wonder why we hate ourselves?,” she fulminated. (You didn’t want to hear her the night “Hamlet” snagged the trophy in 1948.)

The biggest best picture surprises have come in four flavors, starting with the Groaners — expensive, bloated blockbusters boosted mainly by studios’ desperate bloc voting. MGM’s 1962 “Mutiny on the Bounty,” Fox’s “Cleopatra” a year later and U’s 1970 “Airport” had no chance to triumph, but such nominations comforted nervous job-threatened moguls.

Arguably the last big-studio Groaner was 1972’s Fox/WB co-production “Towering Inferno,” though one pundit’s classic romance is another’s “What the heck?” “Tell the truth,” mocked the Philadelphia Daily News in 1990, “when you saw Patrick Swayze and Demi Moore making naughty pottery in ‘Ghost,’ you weren’t thinking of the movie as an Oscar contender.”

A handful of omissions make for Oscar’s biggest headscratchers: 1963’s “Hud” (seven noms) likely has “Cleopatra” voters to blame for  being elbowed out of the main race. And it seems inconceivable that six years later,  “Hello, Dolly” should push out “They Shoot Horses, Don’t They?,” nominated for nine other awards.

Among Oscar maniacs, such puzzlements are as alive today as ever.