This hand brings up a couple of interesting side questions. First, is there value in playing this 1S rebid as a 100% force and if not what is the top end? And second, could it ever be right to make an immediate raise of spades with 3-card support.
If the hand in question were a little better where game is more probable, I might be tempted to raise spades with:
Q10x
A873
A9432
x
On the auction, pard is more likely in Walsh style to be 5422 or 5431 than to have a concentrated 4432. Might not this hand make more tricks in the Moysian fit?
Even AJ93, x, xxx, AKxxx could produce a spade game but NT would be ugly.
I'm sure I'm the minority here but I would be sorely tempted to bid 2S on this example hand.
On the given hand I rate 1N the best but would be very tempted at MPs to make the pass; at imps, I hate to give up on a pard who holds:
AKxx, KQx, x, A10xxx and is waiting to show delayed support over my 1N bid.
WinstonM