Source: http://www.andrewrobson.co.uk

If one opponent plays a critical card in a suit, his partner is twice as likely to have the adjacent card in the same suit. This is because of the Principle of Restricted Choice (“PRC”) – a mathematical theory that was found to have relevance at the bridge table by Terence Reese. He first expounded the theory in his epic book “The Expert Game”, written in 1958 – an inspirational read for any ambitious player.
Dealer South N/S Vul| West | North | East | South |
| 1 |
|||
| Pass | 4NT | Pass | 5 |
| Pass | 5NT | Pass | 6 |
| Pass | 7 |
Pass | Pass |
| Pass |



























