The upshot? Top submissions in the gi were armbars (8), toehold (6), triangle choke (6), bow and arrow choke (5). Top submissions in no-gi were RNC (16) and kimura (6).
By percentage, 17% of the submissions in the gi came from armbars, 13% from toeholds or triangles. No gi percentages were even more stark: 34% from RNC, 13% from the kimura.
The combined tally is also interesting: RNC (17), armbar (10), triangle (8), toehold and kimura (7). You could call these the five most important submissions in jiu-jitsu/grappling.
This research, if I remember correctly, pretty much confirms the work Lloyd Irvin did years ago in analyzing submission rates in the Pan, the World Championships and (I think) the Brazilian nationals over the years. It played a pivotal role in his decision to emphasize techniques like the triangle and the kimura, and more recently the bow and arrow choke, for his competition team.
What is interesting is that no Lloyd Irvin fighters are especially known for their armbars. I would be curious to know if Lloyd has made a discretionary call when it comes to armbars in competition that goes against the grain of the data.