25€ 5max HU 97o river line?

The question I would ask myself here is do I beat some of his value hands. If you think he can do this with some 6x I would just bluff catch. This run out gto wise is better for you that it should be for him. Nevertheless there are not much hands to tripple barrel at all that make sense on this dry board. If I think that he is a reg that likes to tripple barrel to often I would just bluff catch. I you shove I would call in his shoes any T and some 9 too just because I know its rather unlikely that you have an ace.

@maniac OP is not repping an Ace. He's repping a straight or 2 pairs.
@OP I think you're right that we're not beating V's value range, therefore it's shove or fold decision. I personally would fold, but your logic seems sound. The main question is whether you can get him to fold Ax. If he's competent, then he should be folding.

How well does villain know you?
If he knows you're capable of bluffing here, he could quite easily call w/

Well obviously as we speak about anonymous site and I change nick between almost every session there is not much history. Though if villain happens to be regular he might be detecting my playing style. This session was first time I saw this nick but we have played at this point for two hour or so in same tables. So sure he can probably assume I might have bluffing range but its obviously board where draws are very rare with turn being rainbow board.

I would probably only bluff with 97 and 98 combos to be honest. Point is in villain shoes I would have difficulties to find those bluff combos and imo most regs will be underbluffing this spot. Probably me included. If I think about my value range combo wise. So A2o, A2s, A6o, T9o, 78o would make 35 combos. I could include A6s, T9s and 78s or some combos of those but I might raise those sometimes preflop so just left them out. If I bluff every 97 and 98 it would make 24 combos. For villain facing river shove he need to call 3280 to win pot of 9360 so he needs to be good 35% of time. So 24/(24+35)*100= 40% of time I would be bluffing. If villain hold e.g. A5 those value combos would drop to 29. Of course I might also have few more value combos from those suited hands but occasionally might also x-r flop with e.g. A6. So yeah I think bluffing all 98 and 97 would be exploitative line but if I did it with only offsuit hands it would make 18 combos. So 18/(18+29)*100= 38% of time bluffing.

Preflop I would check lot of weak Ax both offsuit and suited. Being 23bb deep I dont like shoving much and dont usually want to bloat pot with weaker Ax with normal raise. So in river I could have A2 and also A6. As said because my range is more capped than villains I would not x-r flop almost ever versus reggy player. Rare Ax+ I want to use as balance for my capped range. Though hand like A6 can be very good for x-r anyway and as balance we can sometimes get more creative with gutshot type hands. Maybe also oesd but nasty thing about using that is if we happen to face 3bet. Though villain should mainly respond by calling or folding.

Anyway as conclusion I would say this is definitely fine play some portion of time.