This is a discussion on $2 NLHE 6-max: Suited ace vs. 3 bet within the online poker forums, in the Cash Game Hand Analysis section; PokerStars Zoom, Hold'em No Limit - $0.01/$0.02 - 6 players
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UTG: $4.17 (209 bb)
MP (Hero): $2.06 (103 bb)
CO: $7.46 (373 bb)
3-bets from the bb are supposed to be slightly stronger than usual due to the incentive to call from the big blind (low price and closing the action).
In this situation, A7s is a standard fold. I think you're supposed to continue with something like ATs+, KJs+, 88+, AQo+ (+ maybe some wheel aces at some frequency to balance your value 4-bets). Either way A7s just doesn't perform well enough against villains range. Some implied odds for hitting the nut flush (draw) but huge reversed implied odds if you can't get away from TPWK.