Spy on an alien planet with a game similar to Go (the strategy board game)

This is something I read in the mid-to-late 1980s, probably in a thick collection of short stories.

A man who is acting as a spy or maybe just a researcher goes to an alien planet. The aliens of this planet are human-like (or possibly a human colony planet), but are very xenophobic and do not allow what they consider aliens in their society.

The protagonist has become fairly expert at a game that they play on the planet, which for some reason I am thinking had similarities to go (aka weiqi, igo, or baduk), and has decided to participate in a large regional or global competition.

Much is made about the fact that in a critical game against one of the planet's masters, the protagonist attempts a kind of three-pronged attack (called a "triple push"?) when normally even a double-pronged attack is considered nearly impossible to pull off. He ends up losing the game but comes close enough to winning that it causes a stir, and as a result he is discovered by the local authorities. I think it's revealed that they've known he was an outsider for some time but tolerated him for reasons I can't recall.

The only other thing I remember is that, while being taken somewhere in a vehicle on the alien planet (on the way to the tournament?), the protagonist is deeply frightened by the experience of being on a highway due to the apparent insanity of the traffic system, which has rules he doesn't understand.

I posted this on a different forum, and several people suggested Iain M. Bank's "The Player of Games", but I don't think that's it because I'm fairly sure this is a short story and not a novel, and ISFDB doesn't show "The Player of Games" being included in any collection. The two things that stand out most in my dim memories are the "triple push" gambit (which fails) and the part about being terrified in the vehicle -- does anyone recognize either or both of those?