Shihonage and tenkai kotegaeshi

Everybody pretty much does some form of shihonage. It is one of the fundamental ways to force somebody to the ground. Most everybody does some variation of a two handed grab, turns under, and forces uke down backward. But perhaps some folks don’t know that there are (at least) two very common forms that appear in randori.
.
Tomiki, when he started formulating the fundamental randori no kata, had both variants in the kata. He called them shihonage and tenkai kotegaeshi. At some point he combined these two into one technique called shihonage in the 17 basic forms.
.
The differences between the variants mostly wash out when tori is able to take a two-handed grip on uke’s arm, but if tori is only able to get one hand on uke’s arm, the technique that pops out depends on the relationship. A cross grab (aihammi) results in tori’s strength being behind uke’s shoulder, so you get the standard shihonage as above. A mirror grab (gyakuhammi) results in tori’s strength being more off to the side of uke, so tenkai kotegaeshi results, similar to the model below.