Chess doesn't have less variations than toribash at all? If you add in every single mod then MAYBE, but that's also why true chess computers are very difficult to beat unless you're a genius yourself playing against them. Each movement is represented by a 20 character value that's visible if you type /opener[0/1] in the game and it will look like this: rrrrrrrrrrrrrrrrrrrr-- if you relax all first turn. There is r which stands for relax, h which stands for hold, -- or ++ shows whether the hands are in a grabbed state or not, and b which stands for bend i presume. While this code doesn't specify contract or extend, each turn has this code. By recording the exact code for each turnframe for each character(tori and uke) and inputting the result[relax all from frame 1 vs relax all from frame 1 = draw 100% of the time for example] you're left with a tree diagram that has multiple winning paths and losing paths.

There's the possibility that I overlooked a variable, but theoretically the possible amount of moves within a single game of chess are over 288 billion according to google, I don't think toribash even hits anywhere close to a million if you're talking about a single mod.

The variables I have:
2 Characters
2 Hand positions
2 Hands
4 Joint positions
20 Joints

Unless I'm forgetting something huge there's no chance this outweighs the possibility of unique positions in a single chess match.

Edit: Actually I did forget one, Human Error, but this will still lead to the result of a joint moving a certain way so this has no quantifiable value, or rather, it doesn't affect the end result at all.