First post to this Forum. So in National Tournament play in Las Vegas, my partner, sometimes known for opening light (in any seat), opens in second seat with 1 Spade. I respond 2NT (my partner Alerts and explains to the inquiry that it is Jacoby 2NT). Opposition passes throughout auction. My partner then responds, "4 Spades." I took it as a 'stop here' signal. I expected a more or less common response of showing a singleton or void at the 3 level or a particularly long side suit at the 4 level. I stopped bidding. It makes 7 Spades. My partner was a bit put out saying I should have continued on with the bidding to explore slam possibilities. I did have a hand that would definitely warrant exploring a slam: Qxxx Spades Heart void Kx diamond AKQxxxx of clubs Partner did in fact have a full opening hand, 5 spades AK, and the Jx of clubs, with the A of diamonds and 4 hearts of (I forgot) what value to give her 14 HCPs. No singleton or void, no real good outside suit. I would have thought a better/best response to my 2NT to be "3 spades." With this response, I'd explore slam by queue bidding 4C, maybe then her bid of 4D, then 4NT [1430] (or 4H) by me, etc. How would you take the "4 spade" rebid by your partner? What would you have done after the 4 Spade bid? Thanks LEE