Hi johnbeattie85,
if he's really a PS.com TAG his range is pretty wide.
Board: 5d 3h 2c
Dead:
Equity Gewonnen UnentschiedenVerloren Hand
Spieler 1: 44.416 % 42.612 % 3.608 % 53.780 % 55+, A9s+, ATo+
Spieler 2: 55.584 % 53.780 % 3.608 % 42.612 % TdTc
As you see you are even a favorite here so in this case a flop check/raise is fine.
Board: 5d 3h 2c
Dead:
Equity Gewonnen UnentschiedenVerloren Hand
Spieler 1: 48.872 % 46.834 % 4.075 % 49.091 % 88+, AJs+, AJo+
Spieler 2: 51.128 % 49.091 % 4.075 % 46.834 % TdTc
Here a tighter range and you are still a favorite so I think a check/raise is the best you can do.
The 4
totally destroys your equity. I think you can check/fold now (after this hands you should do it in any case as he probably checks behind his non straight hands).
As played I think you can remove all Ax hands from his range.
He may now bet a lot weaker made hands (pocketpairs only):
Board: 5d 4h 4c 3h 2c
Dead:
Equity Gewonnen UnentschiedenVerloren Hand
Spieler 1: 59.677 % 58.065 % 3.226 % 38.710 % KK-88
Spieler 2: 40.323 % 38.710 % 3.226 % 58.065 % TdTc
This doesn't look that bad.
Even if he isn't betting 88 and slowplayed a few straights:
Board: 5d 4h 4c 3h 2c
Dead:
Equity Gewonnen UnentschiedenVerloren Hand
Spieler 1: 84.146 % 82.927 % 2.439 % 14.634 % KK-99, AQs, AJo
Spieler 2: 15.854 % 14.634 % 2.439 % 82.927 % TdTc
As you get 7:1 you need only ~14% equity to make a break even call so you should call now.