I'm assuming you didn't allow CO to donk bet?

Certain LLL flops like 432r can actually favor the preflop defender in 3bp. CO's compressed range has a lot less overcard trash, more lower sets and wheel aces, and a better overpair-to-air ratio. Though ultimately it comes down to what ranges you input.

CO range breakdown on 432r:

BTN range breakdown on 432r:

If you allow for donks the CO will lead these flops aggressively. When CO is forced to check and retain all those value hands, BTN simply checks back because their range is dominated.

Okay, while this makes perfect sense to me, how do we explain the difference between oop and in position? On these kinds of flops, our range is also dominated when we're sitting oop. Oop, we do bet a substantive portion of our range across these flops though...

You have to consider the exact ranges being used, and how that interacts with the flop. A BB 3bet vs BTN range looks substantially different than a BTN 3bet vs CO range.

For example, a BB vs btn 3betting range has a lot of suited 9x stuff, so it's gonna be very aggressive on 9 high boards.

Break down the ranges for different boards, look at the equity/EV distributions, and draw your own conclusions.

In general, monotone flops are usually default rangechecks out of position. Strategically they are very difficult to lead on regardless of the ranges. Low connected boards usually favor the defender not the aggressor, so again, hard to lead these boards out of position as the pf aggressor.

I think fishcheckmate explained some of it very well. It really does come down to what ranges you input for BTN 3bet vs CO and BB 3bet vs BTN. Where BB is going to 3bet less pairs and more SCs. The BTN is going to 3bet some what polar because the BB & BTN are both positions where you can have a flatting range. Some of these middling connected boards such as 984r (BU vs CO) BTN is checking 36%. Where in the other scenario (BB vs BU) the BB only checking 5%. The question is why is BB more aggressive oop on 984r compared to BU IP on 984r? I think BTN flats more 99/88 hands preflop and are not pure 3bets as well as some of the Scs 98s 87s 76s can all be flat. Where BB is going to pure 3bet some of these SCs or at least a 50% frequency.

It gets a little complicated but Peter Clarke comes to mind when he emphasizes the EV of checking and realizing equity. If you look at BTN's range on the 9s-8h-4d (board I used on wizard) there is about 50% of 9x checking back vs Co. Why is this? 9x needs some protection but if you look at CO calling range a lot of K9s Q9s and J9s are folding preflop leaving KTs KJs QJs QTs type of hands, so when a Q or K roll off on the turn you end up making two pair and "coolering" CO top pair hands.

There is also something with the SPR. Where BB vs BTN if you 3bet to around 11bb, effective stacks will be 89bb and a pot of 22.5bb (SPR 3.95) where BU vs CO (3bet to 9bb /wizard) you end up with a 4.66 SPR. The 9bb 3bet is a little bit preflop, but you get the picture. Does BU really want to pile money in with one pair in a 5 SPR pot?

Now when you look at BB range on 984r you see how many SCs are in the range compared to BTN's range in the other scenario for robust equity (playability) where they can barrel off pretty aggressively.

I don't have a clear answer for you, but it is something to do with OOP and equity realization vs IP equity realization, SPR 4 vs 5, the domination of giving a free card to Co where hero makes 2 pair vs one pair, then BB wider range needing more FE with the SCs.

Apologies as I don't write as well as you whiteshark but hopefully you can find the answer in this some where. I'll send this thread to a couple others as well and maybe they can provide some more feed as well. I will input the ranges I see on wizard for the 3 bettor in position scenarios, also will show the defending range of CO / BU both scenarios.

Looking at this above Figure 1 & figure 3 for CO vs BU 3bet pot. CO is going to have more 98s, 99, 88 on the 984r board vs BTN. I think BTN counter acts this by checking back and when turn comes A Q or K the BTN will have more 2 pairs and some stronger top pairs as well to make up for the flop nut disadvantage.

Scenario #2 with BB 3bet vs BU. The SPR is going to be a little lower (4 vs 5) and BTN will have less over pairs in range as you can see JJ+ mostly 4 bets. Sets are pretty neutral but BTN will have more lower sets 44. The SCs also look pretty even between BTN vs BB. The BTN will have a ton of over cards with BDFD in range, but at a big over pair disadvantage, so BB is going to want to size up on these boards 984r boards.

I think this answers your question...

Without seeing preflop ranges, my guess is the IP has a signficantly higher portion of offsuit broadways and the OP player has significantly more pocket pairs, so any sort of low board is going to disproportionately favor IP's range. You can check this assumption by node-locking 100% bet for IP and I suspect you'll see that all pocket pairs are profitable raise against the 100% c-bet strategy for both protection and possibly value. If you don't want this strategy choice for IP (I have no idea whether is good or bad -- I suspect without a donk bet, it's probably not that problematic EV wise), then you'll need to look at reconfiguring ranges to make small pocket pairs weaker on these boards.

Another factor is that checking is just higher EV IP than OOP because we get to immediately see a turn card instead of semi-frequently facing a bet. So the hurdle for EV(bet) to be higher than EV(check) is smaller OOP than IP.

Thanks a lot everyone for your responses.

fishcheckmate as you elaborated, we indeed didn't allow the oop player to donk bet in our sims. This means that the checking range contains all of Villain's nutted holdings and is pretty strong when compared to a checking range that is missing the hands that would donk bet if being allowed to. It's natural that IP is going to check a lot vs. such a strong range, whereas betting frequencies would go up against checks when donk bets would be allowed and checking ranges are weaker.

RunItTw1ce I think you pointed out correctly that the two scenarios I outlined (BU vs. BB, CO vs. BU) come with pretty severe differences in range construction. In essence, the IP pre-flop caller on the BU will 4-bet holdings that form overpairs on a 984r board at much higher frequencies than the pre-flop caller would when being oop on the CO. Oop, we're mixing in way more calls with hands like QQ-TT. As in the logic above, this leads to the oop range being stronger and better protected. It makes sense that the IP betting frequency is lower on these types of boards when compared to a betting frequency that we might adopt oop where a large part of these overpairs is missing in the pre-flop defender's range.

Steve Paul Thanks for the additional remark that EV(check) is higher IP than oop since we realize equity on the turn with all of our holdings after checking back, while we need to fold a portion of our range oop after we obted for a check. This equity denial vs. our check/folding range is just not present when sitting IP, which explains that checking is more profitable holding a positional advantage.

Putting these pieces together, this thread has definitely helped me in my understanding of betting patterns on unfavorable boards.