Pocket Jacks are a great but dangerous hand. While you start out as the fourth best hand in hold’em, you can easily get squashed by a raggedy Q5 or someone hanging around with an Ace behind them. Any KQ combination or above gets you at the mercy of a 50/50 situation.
My advice is you either play Jacks hard with 3.5 to 4x the big blind or you limp/play soft and see what comes on the flop. I prefer to play it conservative and see what comes out. If I see two high cards, I think most times I put a feeler bet out and if you get a caller, you know they probably hit.
If the flop comes out low – the dream flop – then I try to end the hand right there. If someone comes back at you, I think you have to push back and put them in a bad spot. Of course this depends on the cards that come out – if a straight or flush possibility is showing, you’ve got to be more cautious.
With Jacks, you’ve got to play intelligent poker and let your discipline come out. If you feel like you’re beat after the flop, you’ve got to muck even though you started with the fourth best hand pre-flop.