Samuel Johnson, an early lexicographer, said, "Every other author may aspire to praise; the lexicographer can only hope to escape reproach, and even this negative recompense has been yet granted to very few."
    If an opponent overcalls, you ought to be armed with negative recompense: the negative double. Look at the North hand. South opens one club and West overcalls one spade. What would you do?
Without the negative double, you would be in an impossible position. Remember, a two-heart response promises at least a five-card suit. But the negative double solves the problem, showing four hearts and at least enough points to compete to the two-level.
    Since South has four-card heart support, he rebids as if North had responded one heart. Here he jumps to three hearts.
    In four hearts, would you bet on declarer or the defense?
    West will start the defense by cashing three spade tricks, East playing high-low to show his doubleton and probably discarding the diamond eight to advertise his king.
    If West is tempted to shift to a diamond, South will get home. He will win with dummy's ace, play a heart to his ace, cash the heart queen, and draw trumps with the marked finesse through West. Then he will play a club to his ace, lead a club back to dummy's queen, and run that suit with the aid of a second marked finesse.
    But West can defeat the contract if he leads a fourth spade and East ruffs with his heart eight. This effects an uppercut and promotes a trump trick for West. Easier said than done.