With ~35% pot odds and a hand that beats some bluffs and worse pairs, calling the river shove is the standard play.
Flop A♦8♥7♦ is very favorable to CO’s range, and we’re out of position with a medium SPR. With second pair and a backdoor flush draw, checking is the standard line—betting would mostly run into stronger Ax and better pairs. Solver prefers checking almost always, with only a small mix of small bets.
After we check and face a small c-bet, calling with second pair and a backdoor flush draw is standard. The price is excellent and our hand has decent equity versus CO’s c-betting range. Solver mostly continues with a call here, with some 3-bet mixing in.
Turn 7♥ pairs the board and gives us 8s with a 7 kicker. CO still has the range advantage, and solver leans heavily toward checking this card—our hand is strong but not invulnerable, and we don’t want to scare off worse pairs and random floats. The small lead we chose is a reasonable mix, but checking is the higher-EV baseline.
River is a check from us; we’re out of position with a medium-strength hand and a shallow SPR. Checking is the standard line here—betting would mostly get called by better hands and raise our exposure versus a shove.
Facing the 17.9BB shove into 14.7BB, we’re getting about 35% pot odds and need roughly that much equity. Our 8s with a 7 kicker beats some bluffs and worse pairs, and CO can still have some missed draws and thin value. Solver prefers calling off here with this strength of hand.