Yellen hits a ground ball....

FORTUNE -- The Janet Yellen-era Fed has officially begun -- with a bit of a curveball. The markets got what it expected from the Fed in one sense -- another round of $10 billion in tapering of the central bank's "quantitative easing" bond buying program, from $65 billion per month to $55 billion per month. But it also seemed to be caught off guard by a change in the Fed's forward guidance on when it might start to raise short-term interest rates.  

The Fed eliminated the 6.5% unemployment rate threshold, below which the regulator had previously said it would consider raising short-term interest rates. In previous statements, the Fed had made it clear that this threshold was merely a guidepost and not a trigger for higher rates, but the complete elimination of that threshold confirms for market watchers that guessing when rates will eventually rise will be a very complicated exercise.

In a press conference following the release of its statement, Federal Reserve Chair Janet Yellen said that while the 6.5% threshold was an effective way to reassure markets that a hike in short-term interest rates shouldn't be expected anytime soon, a hard and fast guidepost would be less effective as the economy continues to improve. "The purpose of the change is to provide more information, even if it's qualitative information, on how we'll approach the problem" of when to raise rates, Yellen said Unsettling if you're as worried about future employment opportunities for your Grand Kiddies as I am.
However - I'm not rushing to judgment on Yellen quite yet.
A few days ago, I ran across a news item in which some reporter had uncovered an old whitepaper or spreadsheet or SOMETHING in which she indicated she believes such arcane eco-data as the rate at which workers QUIT existing jobs is representative of a handful of under loved minutiae which provide "nuance" to the less subtle but more widely followed headline items in the field.
I sent it out to one of my lists of industry contacts but I sent it via Blackberry (you've probably seen the ""Force Majeure" notice I posted last week) thus I have no copy to post here. Suffice to say, the new methodology might be refreshing and uncover something we've been missing in the "notional" recovery.
Unfortunately, seems to me, this fresh perspective could cut either way.
Yoda       MORE: Janet Yellen loves a quitter So, when will the Fed start to raise short-term interest rates? To predict that, you'll have to start looking at a number of different statistics, just like Yellen is. During the press conference, Yellen outlined several different stats that she keeps on her "dashboard," including broader measures of unemployment like the U6 unemployment rate, the percentage of workers that are holding part-time jobs when they want full-time work, the labor force participation rate, the quit rate, and the share of unemployed workers who have been out of work for more than six months..