I believe that SB pre-flop 3bet sizing is bad.
A concept you can use in lower stakes, even if villain is underbluffing, you have to call sometimes when you are at the top of your range, especially when your hand is under-represented. Yes, SB can have some flushes, but still, on the river he has a very well disguised set and he beats some Ax two pair combos that could have played like that.
Yes, from time to time is good to be calling from the blinds when we are on the top of our range, but from the SB it can get complicated, because there’s still the Big Blind to speak.
As a rule of thumb we are 3-betting more from the SB and calling more from the BB when it comes in fold and we are on the top of our range: nothing new here, we are just mixing our strategy preflop, sometimes calling and sometimes 3-betting.
When we do call from the SB our range becomes kinda capped to some
hands that aren’t good enough to 3-bet and also aren’t bad enough to fold.
Yes, SB’s 3-bet sizing is weird and BU took note of that and made a polarized 4-bet to 2.9x versus SB’s 3-bet.
On the flop, considering SB is a recreational, I don’t love BU checking with its entire 4-bet range, though I don’t think it’s wrong, we could consider some calling aces on SB’s range and hands that will not fold so easily, also taking into consideration that 4-bet’s range of BU x SB can be very wide.
If BU had the ace of diamond on its range, the check will work better. Because in a situation like this, SB had all the combos of diamonds and BU had none, so a c-bet of 1/4, 1/3 of the pot would do the work of protecting BU’s range: A2s-A5s, A9s, ATs-AKs, sometimes QQ, KK, KQs, KJs.
On the turn I continue not loving BU’s 1/3 of the pot sizing, this choice of sizing makes harder to put SB into an all-in pot on the river: so if BU begins to build the pot OTF betting 1/3, it continues to bet 1/2 pot on the turn and a jam becomes easier OTR.
On the river there’s no point on SB’s lead/donkey bet: it should be checking more than betting, but it’s quite clear that SB is playing the hand (set of jacks) and not the range: considering that SB doesn’t own the combos of diamonds, which turns the bet even more loose/fishy/out of the way.
When SB donkeys river, which hands it would be expecting to be ahead? Sure there are some AK and AQ that could call but why not simply check-call a fair bet OTR? Because it would be harder for BU to shove river straight off the bat and hope to get calls, BECAUSE BU haven’t build the pot from the flop.
Lucky for BU, SB had done the job itself.
BU had played better than SB. This hand wasn’t a cooler for the SB, it was poor played OTR.