Edit: as I recall from doing estimating using wideband Delphi circa 2004, the main differences with planning poker as I see it practiced today are that estimates were in real time like days or weeks, and votes were collected and displayed anonymously, though as you would expect there was temptation for people to de-anonymize their own votes.
https://en.m.wikipedia.org/wiki/Wideband_delphi
Edit: as I recall from doing estimating using wideband Delphi circa 2004, the main differences with planning poker as I see it practiced today are that estimates were in real time like days or weeks, and votes were collected and displayed anonymously, though as you would expect there was temptation for people to de-anonymize their own votes.