PokerStars No-Limit Hold'em Tourney, Big Blind is t20 (8 handed)
Hand History Converter Tool from
FlopTurnRiver.com (Format: FlopTurnRiver)
UTG+1 (t3100)
MP1 (t2500)
MP2 (t1380)
CO (t1840)
Button (t1130)
SB (t1950)
Hero (t1500)
UTG (t1480)
Preflop: Hero is BB with 7

, A

.
UTG calls t20,
1 fold, MP1 calls t20, MP2 calls t20, CO calls t20, Button calls t20, SB completes, Hero checks.
Flop: (t140) K

, J

, 9
(7 players)SB checks,
Hero bets t60, UTG calls t60, MP1 calls t60, MP2 calls t60, CO calls t60, Button calls t60, SB folds.
Turn: (t500) A
(6 players)Hero bets t100,
UTG raises to t320, MP1 folds, MP2 folds, CO folds, Button folds, Hero calls t220.
River: (t1140) 7
(2 players)Hero bets t1100 (All-In), UTG calls t1080 (All-In).
Final Pot: t3300
How many mistakes did i make here?
Preflop and flop is fine. No sense raising a lot here.
On the turn, I'm in a lot of pain. AJ, A9 and Q10 have us beat here and they're all possible holdings. If someone is holding 99 they are so horrible it's beyond understanding. When you're playing a draw with 7 opponents, you really have to stick to plan a) hit your draw or be able to fold on the river/turn to any aggression, especially on a super scary board.
All that being said, if I'm going to bet the turn, and I'm most likely betting the turn, I'm betting like I have a hand - 300-350. If I'm raised, I'm done with the hand. I don't go broke on my draws. I either make my draw or steal the pot.
You can also check the turn and see what develops. With seven people still in the hand, on a board like this, someone is going to let you know if you're beat. And if you are, you have to figure out your chances of making a flush on the river and whether it's worth continuing.
On the river, I check fold. I'm quite confident I'm beat.