This hand is in the first orbit of a newly-opened 10/20 NLHE game at Bellagio during a trip in December 2015. I had been running well in 5/10 NLHE and wanted to try 10/20 NLHE since I rarely get the chance to play those stakes. Game opens around 2pm or so, just after lunch, and there was an open seat in Seat 9, so I jumped in. I started with $4000 but there is no cap to the buy-in and there were people who sat down with $10k or more in that game. So even with 200 BB's I was probably buying in for the 2nd or 3rd lowest stack. Within the first orbit of play of the table opening, I get 77 in middle position. I am in seat 9, and action folds to me, I open for $80. The next player to act (seat 1 on the other side of the dealer) calls, and we go heads-up to the flop. Villain is young, appears Asian-American, and has a much larger stack of chips in front of him, looks like he had two $5k chips in addition to a stack around my size, so he probably had $12k-$15k to play with, at that point. Pot: $190 Flop: 722 Hero bets $120, V calls. Pot: $430 Turn: 5 Hero bets $300, V raises to $920, hero calls. Pot: $2270 River: 9 Hero bets $1560, V shoves all in (and has Hero covered). Hero has about $1500 more behind. What is hero's move?