Flop Analysis
Small c-betting is ideal here: we have top set in a 3-bet pot on a semi-wet texture, clear range and nut advantage, and a one-third pot bet both extracts value and keeps our range uncapped.
We play the 3-bet pot well until the river, but once the front-door flush comes in with SPR ~1 and we have the second-nut flush, we should commit rather than check-fold.
Small c-betting is ideal here: we have top set in a 3-bet pot on a semi-wet texture, clear range and nut advantage, and a one-third pot bet both extracts value and keeps our range uncapped.
Solver treats this turn as a real mix between checking and small betting, with a lean toward checking range; betting ~38% pot is close to the small size but a bit thinner than ideal with this exact combo. **Ranges:** UTG's call vs 3-bet, flop-call range is now condensed around strong Kx, Tx, diamond draws, and some slowplayed monsters, while our range is value-heavy but also has many missed non-diamond overs and air that want to give up here. **Board:** The third diamond heavily improves UTG's drawing portion and creates many nut-flush combos for them, while our hand is still very strong but shifts from purely fast-value to more of a bluff-catcher plus strong draw if money piles in. **Plan:** Checking more allows UTG to bluff their non-diamond hands and thin-value bet worse Kx/Tx, and with this hand we can comfortably check-call and realize our equity without inflating the pot against a range that now has plenty of flushes. --- > **Takeaway:** When the flush card hits and ranges narrow, lean more on checking your strong made hands plus draws rather than auto-barreling into a now-strong, condensed range.
Note: Turn bet is slightly over-aggressive in a spot where range prefers to check and realize with very strong hands; not a blunder, but checking is higher-EV overall.
With SPR ~1 on the four-diamond river and holding the king-high flush, we should mostly commit the stack rather than check and face a polarized shove where we end up over-folding. **Ranges:** After 3-bet, flop bet, and turn bet, our range is very value heavy and contains many flushes and strong Kx; UTG, having just called down, is somewhat capped away from the very nutty region and contains plenty of worse flushes and some Kx with a diamond. **Board:** The fourth diamond removes non-flush value and pushes both ranges toward a "flush or nothing" structure; second-nut flush performs extremely well in this topology and wants to drive the action, not bluff-catch. **SPR:** At roughly a pot-sized remaining stack, GTO strategy is to commit a large chunk of the range here; checking transfers the leverage to UTG and puts our high-EV hand into a difficult bluff-catching node it was not meant to occupy. --- > **Takeaway:** When you reach a river with SPR ≈ 1 and hold the second-nut flush in a 3-bet pot, default to jamming for value instead of checking into a tough bluff-catching decision.
Note: Checking river with second-nut flush at SPR ~1 passes up a strong value-jam spot and forces our hand into a difficult bluff-catch node it should mostly avoid.
Once we check and face a pot-sized over-jam getting 3:1, folding the king-high flush is reasonable, especially with K♦ blocking several worse flushes and bluffs; population at NL200 underbluffs this line on a four-diamond board. **Math:** We need about 25% equity versus UTG's shoving range; if this range is heavily skewed toward A♦X and some slowplayed nutty hands, our actual equity with K♦ is likely below that threshold despite the strong absolute holding. **Blockers:** Holding K♦ removes many of UTG's king-high flushes and K♦-based semi-bluff candidates, which is bad for a call because more of their remaining jam range is A♦X and fewer are dominated flushes. **Ranges:** GTO mixes here between folding, calling, and jamming depending on hand class; given the line we chose (river check) and typical underbluff tendencies, weighting to the folding branch with this specific blocker configuration is defensible. --- > **Takeaway:** If you arrive at a four-flush river having checked and face a huge shove, strong but dominated flushes with bad blockers like K♦ can be folded, especially versus underbluffing live or mid-high-stakes pools.