The Two-Thirds Rule Explained

Two hypothetical examples will illustrate why the two-thirds rule holds water.

Going into Final Jeopardy!, Aaron is in the lead with $12,000 and Zach's in second with $7,000. For simplicity's sake, we'll say the third player finished Double Jeopardy! with a negative score and is therefore not a Final Jeopardy! participant.

Zach can't give himself the hidden extra chance of backing into victory discussed in the article, since his score is less than two-thirds that of Aaron's. All Aaron has to do is wager $2,001 and he's out of Zach's range. If he misses the question, he's still got $9,999, so Zach has no chance of backing into victory. The only way Zach can win is if he answers Final Jeopardy! correctly and Aaron misses it.

Let's now say that Zach has $10,000 instead of $7,000. Aaron must wager $8,001 to put himself out of Zach's reach in case they both get it right—which means that if they both get it wrong, Aaron is left with $3,999, giving Zach the chance to back into a win.