What do you think of a semibluff on turn or is it better to just flat?

Poker Stars No Limit Hold'em Tournament - t/t Blinds - 8 players
DeucesCracked Poker Videos Hand History Converter

UTG: t1484 1 BBs - VPIP: 9, PFR: 9, 3B: 5, AF: 2,0, Hands: 120
UTG+1: t1798 1 BBs - VPIP: 50, PFR: 17, 3B: 0, AF: 4,0, Hands: 6
MP1: t1454 1 BBs - VPIP: 29, PFR: 6, 3B: 0, AF: 2,5, Hands: 17
MP2: t2996 1 BBs - VPIP: 33, PFR: 10, 3B: 7, AF: 0,8, Hands: 40
Hero (CO): t1121
BTN: t1449 1 BBs - VPIP: 17, PFR: 0, 3B: 0, AF: 0,0, Hands: 6
SB: t1714 1 BBs - VPIP: 11, PFR: 0, 3B: 0, AF: 4,0, Hands: 27
BB: t1484 1 BBs - VPIP: 15, PFR: 13, 3B: 14, AF: 0,0, Hands: 99

Pre Flop: (t0) Hero is CO with 9 Q
1 fold, UTG+1 raises to t60, 1 fold, MP2 calls t60, Hero calls t60, BTN calls t60, 2 folds

Flop: (t240) Q 8 8 (4 players)
UTG+1 bets t120, MP2 folds, Hero calls t120, BTN folds

Turn: (t480) T (2 players)
UTG+1 bets t240, Hero raises to t937, UTG+1 calls t697

River: (t2354) 4 (2 players)

seems like a bad spot to raise on turn. wouldnt you be calling with flushes, str8s, and often boats?

It's not really a semi-bluff. That's when you bet or raise hoping to fold better hands, but if called you still have good outs. Another way to think of it is, you don't yet know if you are bluffing with the bottom of your river range or value betting the river nuts but you would want to do both of those things so the bet is good.

In this case you have a medium strength hand, which can't fold out much better (stronger queens maybe). If called you have 3 outs to a straight which is going to be not much better than a bluff catcher on the river and 2 good outs to the 2nd nuts - full house. Just call and see if you can win at showdown (I'd fold most rivers though if he keeps betting)

The archetypical semi-bluff on this board would be something like AJ, which can fold out hands that beat it such as bare T, Q, or improve to the nut flush, 2 straights, (top pair might be good sometimes too). More advanced players who think in these terms would also like it as it has the A blocker to a chunk of his calling range, but the outs are the key point.

Wanted to rep flush on turn to fold out Qx or, maybe, chop pot in case if v calls (not so often as we see).

^ Ok, but then presumably you would also do that with any weaker hands (i.e. better candidates than TPNK), so therefore it's tempting to do it a lot, and therefore villain should be suspicious and call wide.

I would have expected him to fold his exact holding - also non-diamond draw QJ, KQ, AQ, KK and maybe AA but that isn't much of a bluff target and you are just value-owning yourself against the stronger hands.

Agree.