The $2/$5 tight reg who check-raises the turn after calling the flop has two pair or better. Not a draw. Not a bluff. He got there or he was already there.

Why they do it

$2/$5 regs who take two streets to check-raise have thought about it. They called the flop to keep the pot small and then pulled the trigger on the turn when they felt ready. This is not a semi-bluff spot for this player type. They have a real hand.

The adjustment

Fold one-pair hands. Call only with strong draws that have enough equity to continue. Raise only with the nuts. This is not the spot to find out - you already know.

What it's worth

Calling a $2/$5 reg's turn check-raise with top pair and paying off the river is $150-200 in avoidable losses. Just fold the turn and move on.