Imagine you are on Who Wants to Be a Millionaire?. You have just won £500,000 and cannot go home with less than £120,000. You use your last lifeline (50/50) leaving you a straight guess to become a millionaire or drop £380K. Even though it’s mathematically correct to guess, most people would take the money.
We bridge players are luckier. We have lots of clues in the bidding — or lack of it — the opening lead and the carding signals the opps use. If we find out as much as possible, the final answer is rarely a guess.
Both North and South pushed a fair bit to get to the lousy vulnerable game, against which West led the ♥9. At first glance you have three losers in Clubs plus a huge problem in trumps, but at least you have escaped the fatal club lead. You take three rounds of Hearts and ruff one in hand, then do the same in Diamonds and ruff one on the table. Another Heart ruff in hand works, East throwing a Club, and another Diamond is likewise ruffed in dummy. With 8 tricks in front of you and A 10 of trumps facing Q 8 in dummy, you exit a Club. West ruffs the third Club as he only has trumps left and leads the ♠6 at trick 12.
Now then, here’s your 50/50 to win a million or go one down — shame to get it wrong now! If you’re clear-minded enough, you will see that it’s not a guess at all! If West had the King of trumps, East could have switched to a Spade to beat you when in with the Club. You play small from dummy and claim your million.