Zero.

That is the number of players the New England Patriots signed during the opening day of free agency Tuesday. And the Green Bay Packers. And the Seattle Seahawks.

And the Detroit Lions.

There was a flurry of activity in the moments after free agency opened at 4 p.m., as more than 30 players flew off the board in just a few hours. But the Patriots, Packers, Seahawks and Lions did not sign any of them.

Yet while teams like New England and Green Bay get the benefit of the doubt for being shrewd and avoiding the kind of bloated free-agent deals that are handed out on this day, the Lions drew criticism from some of their fans for their idleness.

Many of the whom, no doubt, also yelled at the Lions for handing out so much money to Matthew Stafford, Calvin Johnson and Ndamukong Suh. Try to figure that one out.

One person asked me on Twitter whether the Lions got the memo that free agency began on Tuesday. Like Detroit accidentally hit the snooze too many times and missed free agency or something.

Come on. This was calculated. And given some of the contracts that rolled across the ticker Tuesday, the Lions' decision to let the market come to them appears to have been a good one.

Jairus Byrd got $56 million from the Saints (and $28 million guaranteed). Tyson Jackson got $25 million from the Falcons. Rodger Saffold -- yes, that Rodger Saffold -- got $42.5 million deal from the Raiders, with $21 million guaranteed

No disrespect to Saffold, but that's some ridiculous money, and probably a contract that Oakland will come to regret.

The Lions sat this one out, but it had more to do with fiscal restraint than anything else. And there's no reason at all to panic.

Sure, some of the top safeties are already gone, including Byrd, T.J. Ward (Broncos) and Donte Whitner (Browns). But Chris Clemons and James Ihedigbo are still available, and either would capably replace Louis Delmas.

The receiver market, meantime, was flush to begin with and has hardly moved at all.

Seattle's Golden Tate reportedly will visit the Lions on Wednesday. He's not only one of the most prized receivers on the market, but a perfect fit for Detroit's offense.

Another wideout, Pittsburgh's Emmanuel Sanders is still available too. He's expressed interest in the Lions and would be a fit for the slot.

It's easy to grow impatient with Detroit, which has so many holes to fill, yet remained idle as other teams seemingly addressed their needs. But don't you remember a day when the Lions buried themselves with bad contracts? The kind of contracts that surely were handed out Tuesday, and celebrated?

And the kind of contracts that will turn into dead money in just a couple years?

It's too soon to say whether this conservative philosophy will be a successful one. But it's also damn foolish to criticize the Lions for side-stepping the ridiculous money that was handed out Tuesday.