So I recently heard Uri Peleg say that the ideal OOP 4bet sizing is full pot if we can only choose one size (he did mention the possibility of exploitatively using more than one size). I have noticed that the GTO Wizard OOP 4bet ranges are also set to full pot.

I had always learned that 2.5x was the best 4bet sizing. Maybe it is still the best sizing for practical play? Or maybe I just learned it wrong?

2.5x vs. full pot is a huge difference, so I am curious to hear what you guys think about this spot.

Thanks for any help!

Is full pot to a larger size then? That encourages more polarised 3betting IP as you are never calling the 4bet.

In a pool where players call more 4 bets instead of just folding or jamming our 4 bets want to be more linear. In that case I took the approach to use a smaller 4 bet size keeping opponents in the pot with an overall weaker range. That’s been my approach for the smaller stakes games I’m in. I’d be curious to hear his reasoning for that sizing.

It depends a lot on positions...
Bvb your opponent has a polar 3bet range with lots of trash, so you can play around with different 4bet sizings and 2.5x might work well in theory (though in practice people miss trash so you're probably better off going bigger).
But if it's CO vs BTN or EP vs MP where the 3bet ranges are very strong/playable hands, than 2.5x is just too small, 3x performs better and still forces people to flat a lot.

Always think of the ranges/sizes as pairs. If the 4bet size is bigger you're making a different hand in your opponent's range indifferent between flat/fold vs the 4bet. EP vs MP you're targetting hands like 78s and pps, bvb probably targetting hands more like KJo Q3s etc.

Full pot is just what happens when you mash the pot button... it's a bit bigger than 3x.

Unfortunately, he didn't give his reasoning in his Upswing course. He just said that it is what solvers like to do. He quickly went on to talk about which individual hands like to 4bet big vs. 4bet smaller.

Thanks Sirrybob, that is interesting stuff! GTO Wizard does go a bit smaller BvB and a little bit bigger than 3x in it's complex 50nl ranges. That makes a lot of sense. After all, the GTO pre-flop charts encourage people to 3bet a lot of trash BvB like T7o or 84s. I might experiment with going bigger UTG-CO than I have been. Heck, I might even go bigger BvB. People do seem to go tight and linear BvB and leave out a lot of the polarized trash. I have just been spamming 2.5x sizings because I that it what the RIO coaches usually did several months ago when I was watching their videos... 2.5x OOP and 2.2x IP were the most common sizings 100 BB deep.

When Uri Peleg replies to your question about what Uri Peleg said, and no one realizes :P

Optimal 4bet size is mostly based on SPR.

You can and should 4bet huge 200bb deep. At lower stack depths, like 50-75bb deep you should either minclick or 4b shove.

There's a trade-off between applying pressure without overcommitting. Then there are more nuanced ideas like going smaller against polar ranges and larger against linear ranges.

Comparing multipliers and pot% is kind of meaningless. Raising 100% pot can give you drastically different multipliers depending on the spot.

I have long suspected 0NoobiePoker0 is not who he says he is

LOL why do you suspect that?