In “Stage Blood,” his 2013 memoir about his years at London’s National Theatre, Tony-winning director Michael Blakemore, director of “Noises Off,” among other stage successes, described the absolutely essential goal in the rehearsal room when a great play is being freshly tackled.

“Every word that is uttered, every action the play requires, has to be particularized through the personality of the individual performing it,” he wrote. “It has to be translated into a second language, the language of acting.”

I happened to be in the midst of reading Blakemore’s book as I encountered just that variety of achievement the other night, in a small black-box theater on Manhattan’s Upper East Side. There, on the stage of Hunter College’s Frederick Loewe Theater, playwright-director Richard Nelson is mounting his adaptation of Chekhov’s “Uncle Vanya,” in a heart-piercing production as sublime as I’ve ever seen Chekhov performed.

That “language of acting” thing? Nelson has it figured out here, on the type of evening when you can confidently say that you know truth when you see it flashing before you. In a fleet and satisfyingly compact hour and 45 minutes, a cast led by Jay O. Sanders — supplying as the title character the most accomplished performance of an estimable stage career — manages to expose the raw essence of a tragicomedy that can easily slip through the fingers of less skillful hands. On this occasion, a playgoer leaves the theater with a new depth of understanding of the desperate sorrows of Vanya and Sonya (Yvonne Woods) and Elena (Celeste Arias), a grasp so complete that you might even catch yourself thinking, “Oh, now I get it!”

One of theater’s most pleasing seductions is persuading you that the version before your eyes is the production you have been waiting for, the one that finally illuminates the elusive psychological corners of a great play–terrain you may not even have been aware was discoverable. Every time you sit down to the revival of such a play you should feel this is a possibility. And of course, that there will be many occasions on which the proceedings will fall short of that goal.

A lot of thoughtful minds met in preparation for the latest classic at Washington’s Folger Theatre, and unfortunately, the results illustrate the latter point. In the sort of adventurous move for which the company has become ever better known, Folger, with the help of some theater and music scholars and a British funding source, resurrected a version of “Macbeth” that became popular after the restoration of public theater performances in England in the 1660s. The goal of reviving William Davenant’s inferior 17th Century version of “Macbeth,” one that rewrote Shakespeare’s poetry, deleted the priceless Porter scene and turned the Weird Sisters into a Restoration-era version of the Andrews Sisters, has academic merit, and to Shakespeare lovers, a certain curiosity value.

But in this case, the director, Robert Richmond, appears not to have trusted that most vital language — the language of acting — quite enough. Onto the play he added a shopworn device: the bedraggled inmates of an insane asylum are pressed into service as a company, to perform this raggedy “Macbeth.” As the asylum guards compel the “actors” into the performance, an audience, seeking a rationale for this framing mechanism, are cast adrift. Instead of giving this bastardized account an unfiltered hearing, we have to try to make as much sense of the director’s manipulations as the of Restoration-era adapter’s.

What goes wrong with Richmond’s “Macbeth” is clarified by what goes right with “Vanya,” a production that began life at the San Diego-based The Old Globe. Nelson has in recent years honed a distinctive directorial style, mostly through his own work, especially, the quartet of “Apple Family Plays” and the trilogy called “The Gabriels.” Each is a comedy-drama set in a household in upstate New York, organized without much visual embroidery around a meal and a matrix of family matters that reflect social and political issues affecting us all. The actors in these productions speak in intentionally normal tones of voice, and if you have trouble catching every word, Nelson has said he doesn’t much care.

“I’m trying to create a world that is true and truthful,” he told me, in an interview last year, at the time a tour of “The Gabriels” stopped at the Kennedy Center.  “I wanted it to be conversational. Not naturalism, not realism, but a kind of verisimilitude: not real, but truth.”

It is that aspiration that colors every moment of Nelson’s “Uncle Vanya,” which begins much as the “Apple” and “Gabriel” plays do, with a family setting a table. The dish in which the production specializes is fully revealing the anguish of Sanders’s Vanya. He’s a man who’s been grievously overlooked. Managing his family’s rural Russian estate — in the control of his absentee brother-in-law Alexander (Jon Devries), a fatuous, retired professor — Vanya wants what Alexander has, namely, the devotion of Elena, who is married to the much older pedant.

Some productions of “Vanya,” even good ones, lose the poignant thread of the narrative by shifting the emphasis onto another bit of unfinished passionate business, the attraction between Elena and the pensive doctor, Astrov, played by Jesse Pennington, in yet another of the production’s remarkable turns. (The play is nothing if not a catalogue of dashed expectations.) Nelson and Sanders and company, though, by distilling the text to a seemingly fresh variety of conversational truthfulness, make Vanya’s silent suffering feel brutally real. And when in this instance Vanya’s patience finally runs out, Sanders’s explosion is nothing less than cataclysmic.

Uncle Vanya, by Anton Chekhov, translated by Richard Nelson, Richard Pevear and Larissa Volkhonsky. Directed by Nelson. Set, Jason Ardizzone-West; lighting, Jennifer Tipton; costumes, Susan Hilferty and Mark Koss; sound, Will Pickens. With Alice Cannon, Kate Kearney-Patch, Jesse Pennington. About 1 hour 45 minutes. $15-$37. Through Oct. 14 at Frederick Loewe Theater, East 68th Street and Lexington Avenue, New York.

Macbeth, by William Shakespeare, adapted by William Davenant. Directed by Robert Richmond. About 2 hours 50 minutes. $27-$79. Through Sunday at Folger Theatre, 201 E. Capitol St. SE. or 202-544-7077.