As we know, optimal third-street play is largely based on the game's ante/bring-in structure.

Standard stud structure is an ante of 10% small bet, bring-in 50% of small bet.

I am playing regularly in a game that has a 20% ante and a 40% bring-in.

Intuitively, this is what seems correct to me, relative to how one would play in standard structure:

- See 4th street a bit more often in pots that are uncompleted (and that you have a reasonable suspicion won't be completed). If a standard 8-handed VPIP is 25%, you want to be around 30%.
- Be extra wary about calling completions, since completing is costing you 10% more than it would in a standard structure.
- Attempt steals more often.
- Attempt to isolate more often.
- As players sit out or leave, widen starting range dramatically and be very aggressive on third street, especially pouncing on opportunities where the rest of the table is not adjusting to the changing conditions.

In general, the 20%/40% structure is beneficial to an aggressive Hero facing a lineup of overly-nitty Villains. (Though of course, a loose game is fine too, as always). In any case, a nitty Hero (20% or less VPIP) is in trouble in the game, regardless of how loose or tight it is. If he maintains 20% as the game goes to 6-handed or less, Hero will be hemorrhaging due to the ante.

Thoughts?

Don't agree necessarily that you should be playing looser with fewer seats. With 8 players paying the ante and one player forced, there will be 2sb in the pot. With 4 players there will be only 1.2 sb in the pot. That shortens your steal odds dramatically, meaning you need to be successful in taking the pot uncontested more often (per attempt) in order for opening to be profitable by itself.

You should still play the best hand for value, and with fewer players in the pot you will find yourself with the best hand more often, but I wouldn't think of it as loosening your Third street standards. If anything you need to have a slightly better hand to open than in a full ring from the same position (same number of people to act after you), to compensate for the smaller starting pot.