This question is one near and dear to my heart.

If it were up to me, I'd try new stuff out a lot more than I do.

My ideal situation would be to run stuff in defined seasons. Maybe a dozen sessions, plus or minus based on what actually happens during sessions. Then move on to a season of a different game. We could return to do subsequent seasons of games if we wanted, and maybe we could go into another season of the same one if we loved it (with a quick break to give time to develop things).

In between seasons, I'd love to run a pilot of a game that I've never played before. Just do a single session or maybe two, with no expectation to keep it going. If everyone loves it, great. It could be expanded out into a season then and there or added to the rota of stuff we mean to get back to.

So in my ideal world, I'd do probably a dozen sessions of a game I knew, then one session of something totally new, with the option of turning that one session into a full dozen. Plus probably one shots here and there if people couldn't show up and it was necessary to fill space.

Not sure what percent to call that. It would depend on how many of those one shots turned into full runs. Let's call that somewhere in the range of 10-20% of sessions.

I don't have a stable group and mostly play at conventions or when my rpg friends come over. I thus tend to play a lot of new games, I try to play new stuff almost half of the time if possible

For board games, it's about 50/50. For RPGs, however, it's about 90% established campaigns vs 10% "something new" (including one-shots and new attempts to start campaigns).

RPGs, we tend to run one game pretty consistently until the end of the campaign (whether "story is done" or "DM ran out of time and can't run" or "y'know what, this sucks balls"), then we usually switch to a different game. We recently stalled on a DCC campaign and the group's now on Traveller (I'm on a sabbatical at the moment or I'd be in there too, but with work being what it's been I need more down time).

Boardgames, though, I try to get a mix. When we met at the games cafe I'd like to try to get three games in a night. One that we know well (Terraforming Mars, say), one that we've played before and are still getting to know (see if it will upgrade to know well), and one we haven't played before.

I've got to work on my Shelf of Shame somehow.

We have a local boardgame club so it is easy to play a new game every month.
RPGs on the other hand ... it is difficult to bring the motley crew up to speed with a new set of rules especially when one of them will not ever read anything you hand out. Doubly difficult if the rules require a different style of play to the groups norm.

Due to being a tabletop content creator there's always the push to talk about something new which is part of why I got into doing this. While I'm not at all about the new hotness, I don't care if a game is hot or new, I do love trying new games.

Given the choice to learn a new game or play something I know I will almost always try something new. Now that said I do try to play that something new about 5 times before making a judgement on it, though some games I know right away they aren't for me after 1 play.

The main problem with this is that my wife, the person I game with the most is the exact opposite. She would always prefer to play something she already knows how to play. She hates learning new games. So this is a constant "fight" in our house.

It's especially difficult with having to isolate due to COVID-19. Normally I get my new game fix on the weekend when I run public play events. I get to try the new stuff with the general public and Deanna can play stuff she knows already. Also I get my fix in so when it's the two of us sitting down to play I don't mind picking up something we both already know.