Avoid leading into the preflop raiser on Ace-high boards, and never turn a marginal bluff-catcher into a shove against a river raise.
Leading into the preflop raiser here is a significant error. This board heavily favors the UTG+1 range, which contains all the strongest Ax and pocket pairs.
Note: Don't lead (donk bet) on Ace-high boards as the caller; the raiser has a massive range advantage and you should check your entire range.
After betting the flop, we have picked up second pair. While we have improved, we are still behind the majority of the range that calls a flop lead.
Note: Betting second pair out of position is too thin; checking allows us to control the pot and catch bluffs from their missed high cards.
The river completes a few straights and we now hold a marginal pair of nines. Betting here is highly questionable as we rarely get called by worse.
Note: This is a clear check-fold or check-call candidate; betting forces Villain to play perfectly by folding air and continuing with value.
Shoving over a river raise with a weak one-pair hand is a massive punt. We lose to every value hand and block the very bluffs Villain might have.
Note: Turning a bluff-catcher into a three-bet bluff on the river is a disaster; Villain's raise is extremely value-heavy on this runout.