Question...in general, let's say in the late stages of a tourney ITM we are shallow 25bb deep, should we be usually 3betting a linear or polarized strategy, is there generally a set rule? Or should it be used hand-in-hand with our position?

I feel like stack size shouldn't matter ALL that much should it? I see a lot of videos saying we should be going linear when deep and polarized when shallow. But wouldn't it make sense to have a mixed strategy? Meaning if we're 80bb deep and 3b a stack 25bb deep and 3bet small with a polarized range, is that so bad a play?

I base my 3-bet strategy on position, effective stack, how frequently I have been 3-betting to that point, and the range of the original raiser (i.e., how frequently they have been raising especially in their relative position).

The less frequently I have been 3-betting the wider my range. Similarly with the opener, the wider their range the wider my 3-bet range.

My range stays very wide if I haven't had to show any of my 3-bets and/or if the ones I have shown have been very strong hands.

My bet sizing though is always the same. 3x vs 1 player when I am in position and 4x when I am not. If there has been a caller then I make it 4x (or 5x OOP). But I tend to be less polarized when there has been a caller.

Everything does change for me though when the effective stack size is < 25 bb's (this includes players still to come). My range shifts radically. All SC type hands are out the window and all AXs hands are in. And I am jamming.

I would say polarized with non-all-in 3-bets, but at that depth you should have some shoves too and those will be more linear. You'll shove more often over late-position raises, generally, due to the wider opening ranges and fewer players left to act.

Well, in the bolded case, the effective stack in play is still 25BB, and effective stack is what you need to be considering, not just your own stack. When the effective stack is deeper, having a more linear 3-bet range gives you more opportunities to win the pot, either preflop, by taking the betting lead postflop, or by being able to commit more chips at the lower SPR when you flop a strong top pair or strong draw.

So do you 3bet smaller at shallower stack depths? Say 20-30bb?

I basically 3-bet jam under 25 blinds.

There are times between 25 and 40 bb's that I raise a little less. But one of the reasons I 3-bet is to create big pots. Another is to get people to fold pre-flop.

I would say you want to have some light 3! At 20-30bb stack depth in specific spots like bb vs cu or button / or small Blind Vs button or cu. You wanna size properly though and smaller than normal to allow for folding if you are 4! Or jammed on with light portion of range. I think one should 3! With some light portions A5s, QJo, J10s etc and super strong portions like QQ/KK/AA. Idk think you gotta look at opponent and 3! Light against some more active players and maybe exploit not 3! Against tighter folks in live mtts.

Might jam hands like 33,44,55,66 in a spot with 25 bb though say sb Vs cutoff when cu opens to a min or a little more and we have say 20-30bb (prolly more leaning at doing this at 25bb or
Less).

Great advice so far in this thread, definitely give each of those posts a couple reads and really try to internalize it. I think there's a lot of ways to go with this but something no one really touched on that we can possibly leverage is perception. I actually like recommending more 3b bluffing at ~20-30bb stacks for my students who have a tight image. I think it's good to attack an opponent who is opening quite widely but will only continue against our perceived strong c-bet with an incredibly condensed range. Say you have a villain opening ~30%+ in the cutoff and you 3b off of ~25bb from the SB and have a nitty image, I think this is a spot a good thinking reg will likely not continue with wider than 88+ AQ+ AJs+ (since they'll assume you're heavily weighted towards value and bereft of bluffs due to your stacksize/position/image) therefore there's quite the gap between their opening range and continuing range. I would say the flipside, when you're both deep stacked in the same positional situation, your 3bets will seldom yield folds since people will be peeling with a wide array of hands due to stack depth/playability/position etc.

Just be aware of how you are perceived at the table by your opponents before you cultivate some of your 3-bet strategies. Typically if you are against a worse player, I'd be focused on what you believe their continuing range to be, whereas, against a strong/better opponent, perhaps focus more on what they perceive your range to be (and how you can manipulate that)

I like to be linear with my jams around 25bbs and less and then polarize my 3bet range with some weaker hands mixed in with monsters. another interesting take away here is when you open and have someone behind you flat with around 25bbs you might now realize there range is likely capped because they likely would be playing for stacks with 88,AJ,AJs+ so there flatting range can be very capped which we can take note of and take advantage of