[Catalog] Add games from sample page to catalog

[edwardchalstrey1]

This feature request is for...

PyGambit

Requested enahancement or feature

Currently there is a page called Sample games in the docs which contains 13 games. We should add these to the catalog.

@tturocy @rahulsavani if you think some or all of the games on that page already have sufficiently good descriptions then I can make a start adding them.

[edwardchalstrey1]

As discussed in the meeting on 12th March '26, most of these will require a bit of work. We also may want to contribute associated tutorials.

[tturocy]

@edwardchalstrey1 @rahulsavani I've now tracked down the examples from Spence's textbook and tidied them up and moved per our naming conventions.

The other low-hanging fruit here would be to migrate both stripped-down poker and Myerson's analogous one-card poker. @rahulsavani How much work would it be to move the uses of stripped-down poker from the test suite so they are pointing to the catalog entry?

[rahulsavani]

The other low-hanging fruit here would be to migrate both stripped-down poker and Myerson's analogous one-card poker. @rahulsavani How much work would it be to move the uses of stripped-down poker from the test suite so they are pointing to the catalog entry?

Stripped-down poker (and Kuhn) are two examples (the other being the families based on Bernhard's exponential-sized RSF examples) where we generate the games in the test suite.

For both stripped-down poker and Kuhn we create and test with two variants, one with payoffs at and only terminal nodes, and the other with non-terminal outcomes too. We can easily just write those to .efgs files but we were, I think, planning on keeping the pygambit code to generate these games. If we don't mind not having that code for stripped-down poker, we could just have two .efg files in the catalog (one with, one without terminal outcomes). Then the actual changes to tests are trivial. I think this is fine because we have the stripped-down poker tutorial. For Kuhn we will want to keep the code from the tests somewhere else as that's the only place it appears currently.

If we agree on this plan, perhaps @edwardchalstrey1 could actually implement this for stripped-down poker?

[edwardchalstrey1]

@rahulsavani I have a draft PR open #767 in which one feature is #758 - I think I should add Kuhn/Stripped-down poker as the first catalog games defined in code with variants (and remove the one-shot trust example I put there as placeholder). If you can let me know exactly where those games are currently defined, with both variants and long descriptions, I can integrate them into this PR - one question would be, should game descriptions for variants differ? A walkthrough of that PR would be good to chat about once you're back, I think the other changes should be uncontroversial (this PR doesn't include the draw_tree visuals I showed yet).

[tturocy]

Stripped down poker, as it comes straight from a paper, seems like a game we should have in serialised format, in parallel to Myerson poker. The version where we put the antes at non-terminal outcomes is a Gambit extension, which we need as examples and for testing.

I can just shift the existing Myerson poker.efg into the catalog and add descriptions without worrying about the stripped-down version, although it feels a bit off given that it's the Reiley version we use in the tutorials (because it is more intuitively specified)