Professinals can play with no or few mistakes on 9x9 but MC bots play
with more mistakes (perhaps one per 10 to 20 moves?) due to the
randomness.  At the two-years-ago event, Zen vs 3 pros, both did many
mistakes and Zen had several chances to win.  At this event, however,
Cho 8p played almost perfectly because he studied 9x9 Go so long (more
than 10 hours) and Zen had no chances.  Hirata 3p (younger pro) did few
mistakes at the 1st game but Zen couldn't take the chance because it was
a very narrow sequence of moves.  As a conclusion, no-miss-play is
required to beat serious professionals on 9x9 :).

Hideki

젠 개발자인 가토 히데키씨가 대국후 한 이야기 입니다.

프로가 9줄 바둑을 따로 연구 했는지 실수가 없어서 이길 기회가 없었다는 이야기네요.

제 견해는 약간 다릅니다.

젠이 9줄 바둑에 대해 따로 노력을 하지 않은것도 있고

그외에도 1년이상 정체된 모습 등을 봤을 때 젠의 한계를 보여주는 대국이었다고 생각이 됩니다.

며칠전 있었던 KGS 2월 9줄 바둑 대회에서 느꼈던 생각이기도 합니다.

9줄 바둑에서 컴퓨터와 프로의 대결이 앞으로 어찌 될지 예상을 해보자면

9줄 바둑이라고 해도 경우의 수가 아주 많기 때문에 완전히 풀리는 상황은 나올 수 없지만

올해안에 컴퓨터를 이기려면 9줄 전용 포석을 수백개 외우고 실수를 전혀하지 않아야 이길 수 있는 수준

다시 말해 프로의 실력이면서 9줄 바둑을 오래 연구해야지만 겨우 이길 수준까지 발전될 겁니다.

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추가

Attached.

Some comments for the games.

1st game: W move 18 should be E3 and the game was over (by Meien O
9p).  W move 32 (D5) was bad (ditto) but Hirata 3p claimed he worried
B C5.  #Professionals spent much time for this game and concluded Zen
had a chance to win (I couldn't follow ;- .  Perhaps, move 35 (E8)
should be C8?  Comments welcome).

2nd game: Almost perfect win by B.  Chang 8p had studied this opening a
lot and had a big confidence.  Ohashi 6p (well-known 9x9 expert) was
very glad because the opening until move 7 practically get concluded as
B+0.5, thanks to Chang.  W E5 (6th) was bad.  #This could be included
in opening books.  Chang also commented he couldn't noticed W F7
(8th) by himself, which is a very good move.  So, without pre-study,
he would be surprised and was hard to win.

3rd game: W F7 was good (perhaps best).  W H2 (16th) surprised Hirata
3p (he commented after the game) but was suspicious.  Perhaps, F4 was
better but either looks lead B win.  Ie, W already behind here.  W E5
was bad?   I'm not sure.  Anyway, B E4 (17th) was good which Zen found
after played H2.  At H2, Zen forecast F4 and (I guess) there was 1 pt
(or less) difference by W E4.  W had a chance to play G5 and start a ko
at F4.  After B G5 (21st), W had no chance.  Almost perfect win by B.

4th game: Some people think Chang intentionally lead a complicated
game (not confirmed :) but Zen did a big mistake (B C4) and lost.
Weak programs commonly played D8 (correct) but Zen found he could kill
bottom W (wrong).  B D8 lead even positions but C4 lead a sure win if
bottom W could be killed.  So, unfortunatelly, this was the natural
choice for Zen.  Two move later (B C3), Zen noticed W could live and
winrate dropped to 30%.  Alas, too late!
#W E2 (14th) is a well known tesuji to live on sides but Zen has no
special procedure for this shape in the simulation.  If the cpu was 10
time faster, Zen could play D8 :).

Overall: I found that when Zen was behind, professionals played the
same moves as Zen's forecast.  This could mean professionals played
without mistakes.  MCTS bots do some mistakes due to the stochastic
behavior, which is a essential (i.e. cannot avoid) weak point of
the algorithm.  More effort would be necessary to build better opening
books, anyway.