The Wikipedia page for quads actually has an ok timeline mentioning also some unratified events -
https://en.wikipedia.org/wiki/Quad_(figure_skating)
Skate Guard did a listing of Canadian firsts which was also mentions some quads:
http://skateguard1.blogspot.com/2021/03/airborne-timeline-of-canadian-jumping.html
Names to be added to the pre-Josef Sabovcik/Kurt Browning era are at least Robert Wagenhoffer (4T but practices only), Campbell Sinclair (4Lo around 1982, in nationals I think), and Mark Cockerell (4T 1981, in national competitions at least). Alexander Fadeev was the first to try a 4T in international competition in 1983. Brians trained 4Ts, but only Boitano attempted it in competition.
It is interesting that the first ratified 4S was only in 1998 (Timothy Goebel), but it has not been a very popular quad among men. It was trained for and sometimes attempted in competition before that - Michael Chack in the early 1990s is mentioned in lists of firsts for it. I have seen in mentioned in connection with Alexander Abt, Ivan Dinev, Takeshi Honda, Ilia Klimkin, and Vincent Restencourt.
The prehistory of 4Lo includes also training for it by Shepherd Clark and Timothy Goebel - these are based on their interviews and news stories. Plushenko trained it a bit later. Before Hanyu got the ratified one in the books, it was attempted in competition by Kevin Reynolds 5 times 2011-13, all with UR or downgrade (national and international). Mroz tried it 3 times in US summer competitions in 2012 and got one fully rotated, but with other problems bcs the GOE was -2.00. Gordei Gorshkov tried in a Russian national level competition in 2014 with a downgrade. Aleksei Krasnozhon tried 4 times in 2015-6 junior GPs and national level competitions, again all with URs or downgrades.
Also 4F was trained for before Daisuke Takahashi tried it in competition: Alexander Abt and Frederic Dambier at least. (Nam Nguyen and Anton Shulepov have dabbled with it in addition to Chan and Orzel.) Takahashi tried 5 times 2009-12 in competition, but never got it fully rotated.
And the same applies for the 4Lz. The guys to train it in the 1990s are reportedly Takeshi Honda and Elvis Stojko. Maybe also Yehven Plyuta in addition to Michael Weiss for whom there is even video evidence as seen above. Plushenko tried it in competition already in 1999. Mroz was apparently the first in the IJS to try it in 2011 - I have not been able to find any attempts between these two times. Adam Rippon and Vladimir Sezganov were also going for it in 2011-2, but neither of them ever got a clean one in competition (incl. later tries).
The 4A has been discussed a lot lately and indeed, Artur Dmitriev Jr is the only one before Hanyu to try it in competition, 3 times in 2017-2019, twice in national competitions and one in an international one. All downgraded.
Nathan Chen is the only one who has done 5 quads (missing obviously 4A) in competition - his record with the 4S is a bit thin, but he tried it again this fall. And he has them all with positive GOE. Hanyu has all but 4F, but no positive GOE with 4A.
Krasnozhon and Uno have tried 4 quads, not 4Lz and 4A. Both have positive GOEs on all of them, but Krasnozhon's record remains a bit thin, Uno is going for all four this season. Boyang Jin has not tried 4F and his 4S and 4Lo are almost ancient (the last ones in 2018-9 and 2016-7 seasons, respectively), but he has also a positive GOE record for 4 different quads.
Add: OMG I forgot Vincent Zhou from the list of guys with 4 different quads with positive GOEs - he has all but 4Lo and 4A. And has tried them all this season. Sorry, Vincent!
The combinations an jumpers of 3 different quads is quite long these days, so let's forget about that.
Was not Stephen Gogolev also rumoured to have landed all 5 quads when he was still with Orser?
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