Sometimes, in a game force situation with a fit, we can make a bid that shows our partner where our short suits are. On this hand, 4♣ by opener after responder bids 2♦︎ would show a diamond fit and a club singleton or void. This is called a “Splinter Bid".
Why do this? It allows partner to better evaluate how the hands match, and whether to go beyond game to slam. It also helps to avoid bad 3NT contracts.
This Challenge Hand is from my new book Two Over One Game Force which will be available to buy for $17 on my website very soon. This 45 page book is a straightforward, clearly set out guide to the latest ideas in the Two Over One Game Force System.