Johan Widerberg did not receive an Oscar nomination for portraying Stig Santesson in All Things Fair.
The film itself begins with Stig played by Widerberg, who is also the son of the film's director, as he is beginning school though he's mostly only interested in sex. Widerberg plays these early scenes without complication just presenting Stig as basically a lusty teenager though with just the slightest hint of a smooth unassuming charm, although really not much of it. This soon leads to the affair with his teacher Viola (Marika Lagercrantz) which happens very quickly. This is not a criticism of the film even though it might seem like a bit of a fantasy though only from Stig's perspective, the ease of the affair does not come from any actual seductive ability of Stig's rather it comes from Viola's personal desperation that we learn more about as the film proceeds. The early scenes are in the view of the fantasy though and Widerberg presents them as just seeming a dream of sorts for Stig who just is enjoying every one of their secluded engagements, which is very different from his family life which is troubled due to his brother being in danger due to the war.
Widerberg attaches the whole affair well to basically just an escape for Stig as there never seems as though he really recognizes the reality of his situation rather just embracing a certain immaturity that is allowed from it all. This changes though when Stig is caught multiple times by Viola's husband and it soon becomes obvious that he is aware of the affair, he just does not care. Thing are only made more complicated as both the husband and wife decide to share their insecurities with Stig, and Widerberg is very good in these scenes by showing basically Stig being forced to snap into reality. The abundance of pleasure as he goes about his days becomes severely muted in Widerberg's performance, and most importantly of all Widerberg slowly moves away from being just that lusty teen. Widerberg subtly conveys a maturation in Stig through his reactions to the desperation that he sees forcing him to realize his own, which only seems to become worse since he is no longer able to escape it through the affair.
One scene that is particularly effective in terms of Widerberg's work is when another girl, one who happens to actually be his age, attempts to seduce him, and Widerberg in his reaction portrays the exact maturation of Stig as he denies the girl, something that would not doubt seem ridiculous out of the Stig in the opening scenes of the film. This is a natural transition made by Widerberg as he presents the boy becoming the man in the way he no longer avoids the complications of life. This soon changes though as well when he stops the affair, causing a great deal of bitterness with the teacher, and Widerberg is good in changing Stig into being defined by a resigned frustration as he can do nothing to change his plight. That is until a more severe tragedy befalls him which instead forces him instead into a sadness, which Widerberg plays well again with that same resigned quality as though Stig is finally aware of what he can and cannot do in life. This is a good performance though I must admit that it is one that I was always oddly detached from. It hits all the appropriate points through the film though it just never quite took that next step for me, although I can see why one could potentially love this performance.