Portisch qualified from the Amsterdam Interzonal 1964, with 14.5/23, in a tied 8th-9th place, defeating Samuel Reshevsky in a playoff match to advance to the Candidates' series for the first time.
Portisch qualified from the Amsterdam Interzonal 1964/23-9th place, defeating Samuel Reshevsky in a playoff match to advance to the Candidates' series for the first time. This was in a tied 8th. This is with 14.5.