Sara Krulwich/The New York Times

Let’s begin by acknowledging that all actors, especially stage actors, are brave. It takes guts as well as vanity to unpack your heart in front of a live audience.

But within that courageous profession, there are those who stand out as particularly fearless. They’re the tightrope walkers, the performers who straddle voids without nets or harnesses, who make you hold your breath in terror and release it in an ecstasy of relief.

Of course with actors, it takes more than guts to command our admiration. In the theater, feats of derring-do don’t count for much without a big emotional payoff or a lightning flash of insight. When an actor goes out on a limb, you need to feel that you’ve been taken there as well and allowed to glimpse a gasp-worthy view you might never otherwise have seen.

Anyone who attended the Sydney Theater Company’s production of Chekhov’s “Uncle Vanya,” seen in New York last month as part of the Lincoln Center Festival, would have experienced a number of expansive views, offered by almost everyone in the cast, directed by Tamas Ascher. But the member of that ensemble I’m focusing on today is Cate Blanchett, whom I’m nominating as the heir apparent to Vanessa Redgrave for dauntless and dazzling risk-taking.

In my theatergoing lifetime, Ms. Redgrave has probably been the supreme example of the tightrope-walking stage star. Though not the most technically accomplished actress of her generation (a mastery of foreign accents continues to elude her), she has regularly and boldly ventured into scary, uncharted terrain.

I remember watching her as the love-hungry Lady in Tennessee Williams’s “Orpheus Descending” and thinking at first how implausible she seemed, with her big flailing gestures and a voice that evoked less the Italian matron she was portraying than an addled Scottish nanny.

But it wasn’t long before her clumsy, extravagant gestures and raw expressions began to assemble themselves into a painful, illuminated map of loneliness and longing, and of pride abandoned for passion. By the end, she had taken us to that place – a geography in which Williams specialized — where love strips its victims of decorum and defenses.

When this Lady died for love, it was not with a graceful farewell but a pratfall. And the image of Ms. Redgrave falling flat on her backside had an echoing magnificence that I’ve never known in any other death scene.

Richard Termine for The New York Times

I thought of that moment when I was watching Ms. Blanchett’s performance as the gorgeous, restless, uncomfortably married Yelena in “Uncle Vanya.” No, Yelena doesn’t die. But as portrayed by Ms. Blanchett, she does fall down, often, in a most unseemly manner. She also weaves, wobbles, stumbles and, for her big love scene, tumbles like an Olympic gymnast recovering from a shaky dismount.

And for not one instant did Ms. Blanchett come across as an actress showing off. No, I was seeing only Yelena, a conscious beauty who knows she is expected to match her exquisite appearance with appropriate poses and movements.

But Yelena is a human being, which in Chekhov’s universe means that grace, poise and equilibrium are at best attributes of a moment. To be a Chekhov character is to lose your footing with regularity and to land with a thud more often than anyone who presumes to dignity would like to think possible.

Though I’ve seen an assortment of accomplished actresses as Yelena (including Julie Christie, Janet McTeer, Julianne Moore and Laura Linney), Ms. Blanchett was the first to make me fully appreciate the character as both a disruptive catalyst and a hapless victim of the emotional turmoil that her very presence stirs up. You felt that this Yelena, while aware of her beauty, didn’t own it in the way that classic femmes fatales do.

As a consequence, I found new depths of pathos and humor in Yelena, generated by the disconnect between a heavens-skimming image and an earth-scraping reality. Pretty women slipping on banana peels have always had their own comic resonance, both gratifying and discomfiting. In succumbing to such indignities, with a wildness that made you fear she might fly away altogether, Ms. Blanchett discovers a new profundity in Yelena. She is truly a figure of comedy and tragedy, which Chekhov’s singularly ambivalent plays demand but seldom receive.

Like most people outside Australia, where Ms. Blanchett cut her teeth onstage, I first knew this actress only for her film work. Judging only from those performances, I would have thought of her as a more likely successor to Meryl Streep than to Ms. Redgrave.

Like Ms. Streep, Ms. Blanchett is a born mimic with an uncanny gift for replicating accents and speech rhythms. (Her Katharine Hepburn in “The Aviator” is as dead-on as Ms. Streep’s Margaret Thatcher in “The Iron Lady.”) And both women project a prismatic, cutting intelligence on screen that sometimes distances them from their characters. You never feel that either actress, in their movie roles, is in danger of losing control.

I didn’t fully register the white-hot energy behind Ms. Blanchett’s composed coolness until I first saw her onstage, when the force of it hit like the blast of an open furnace. That was in the title role of “Hedda Gabler,” another Sydney Theater Company production, adapted by her husband (and co-artistic director of the company), Andrew Upton, which came to the Brooklyn Academy of Music in 2006.

As Ibsen’s thwarted, destructive heroine, Ms. Blanchett laid siege to the stage with a tireless, hyperkinetic interpretation that ultimately warped and melted the play around her. Working in a dybbuk-like assortment of voices, at a pace that suggested a hurricane tearing through (and up) a parlor, Ms. Blanchett’s performance was nearly all radioactive subtext. We rarely saw a Hedda who could inhabit any conventional society, much less be imprisoned by it.

Some critics, including my colleague Charles Isherwood, thought her Hedda was an annoying example of a narcissistic star’s self-indulgence. But I enjoyed Ms. Blanchett’s energy and audacity and, yes, fearlessness. And I felt that if someone could just put this ferocious genie in a bottle onstage, great art would emerge.

Lisa Tomasetti/Associated Press

That’s what happened when she played Blanche DuBois in Williams’s “Streetcar Named Desire,” seen at the Academy in 2009. All the traits and tricks that Ms. Blanchett had brandished so flamboyantly as Hedda were still in evidence in her Blanche.

But as directed by Liv Ullman (best known as the spiritually transparent star of Ingmar Bergman movies), Ms. Blanchett strategically harnessed those qualities. The different vocal pitches were used artfully and sparingly now, to suggest a woman divided between a blithe social surface and an inward, unconquerable despair.

Even more impressively, the energy that had raged in her Hedda hadn’t been extinguished. But it had been internalized. And I became aware, as I never had been before, of the sheer physical, as well as psychic, exertion that the embattled Blanche required merely to keep standing, let alone to sustain her genteel facade.

She didn’t just show us Blanche DuBois versus Stanley Kowalski (played by Joel Edgerton). She gave us Blanche against the universe, and it was some prize fight. We have always known about Blanche’s fear and fragility. Ms. Blanchett made us feel her bravery as well, something it takes an unusually brave actress to do. Seeing her confirm that bravery with commensurate artistry in “Vanya” was a relief and an epiphany, the blazing kind that only daredevil acting can afford.

These expert daredevils make up an elite club in the theater. For me, their ranks include Mark Rylance, for sure (as anyone who saw him in Jez Butterworth’s “Jerusalem” can confirm), Liev Schreiber (on the basis of his stage work in “Othello” and “Talk Radio”), Laurie Metcalf (with performances stretching from “Balm in Gilead” in 1984 to the recent “Long Day’s Journey Into Night” in London), Kevin Spacey (did you catch his “Richard III”?) and Elizabeth Marvel and Bill Camp (for their astonishing work in Ivo van Hove’s actor-flaying productions).

Who are your nominations for this explorer’s hall of fame? And what specific performances took your breath away with their bravery?