Still, for all of the deals that some clubs might like to have back from the winter of 2011-12, plenty have worked out well. From one-year flyers to mammoth megadeals, last offseason featured plenty of successful decisions by teams acquiring talent.
Here's a look at some of the lessons that might be learned from the deals that went right from last offseason.
Read the medicals: Sometimes a player who has had health problems in the past is actually doing pretty well. Several clubs took risks on free agents who had dealt with injuries last winter, but two in particular scored big: the Cardinals with Carlos Beltran, and the Rangers with Joe Nathan.
Each team did its due diligence, acquired all the information that it could, and pulled the trigger on a player with a history of excellent performance, but also significant health questions. In each case, the player had stayed reasonably healthy in his most recent season.
It's also worth noting that both teams committed only two years to the players in question, both of whom would likely have gotten longer deals if not for the health questions. Injury risk is a major complicating factor in putting together a roster, but it doesn't have to be a negative. A smart team can use health questions to its benefit.
There's no such thing as a bad one-year deal: OK, that's not categorically, 100-percent ironclad. But it's awfully close.
What scares teams most, in agreeing to big contracts, is long-term commitments. What many players want most is long-term security. When a team can acquire a quality player for only one year, as the Reds (Ryan Ludwick) and Yankees (Hiroki Kuroda) did, there's almost no chance that the move will really backfire.
Kuroda entered the 2012 season at age 37, with no interest in going more than one year at a time. Ludwick came off a brutal '11 season that saw his value plummet, and he didn't have much choice but to take a one-year pact. In both cases, player and team benefited. Kuroda thrived as one of the Yankees' most essential pitchers and got to play in the postseason for the third time. Ludwick enjoyed a huge bounce-back year in a hitter-friendly ballpark and a power-packed lineup, re-establishing his value for another time on the market this winter.
It's no coincidence that Kuroda has already re-upped with the Yankees, and that Ludwick and the Reds apparently have mutual interest in a return engagement. The deals worked well the first time around.
Buy young: It's a misconception to think that players age in any kind of entirely predictable, linear pattern. That doesn't mean there aren't some trends that are worth following.
For the most part, players peak in their late 20s, and sometimes early 30s. Once they're past 30, they are likely to decline. Not without exception, and not in a straight line. But most likely, a player who signs at age 32 is likely to be less effective over the next four years than the previous four.
That's why younger free agents are so coveted. It's why B.J. Upton commanded such a premium from the Braves -- he's not at the point in his career where he should be declining yet. Last winter provided plenty of examples.
Yu Darvish turned 26 in August. Yoenis Cespedes played the entire season at 26. Prince Fielder turned 28 early in the season. Wei-Yin Chen, whose signing by the Orioles was quietly one of the year's most successful additions, turned 27 shortly after the All-Star break. Jason Kubel, who had a big rebound year for the D-Backs, started the season at 29.
Not every young player is a bargain, and not everyone over 30 will be a bust. But when a team signs a player who's still in his 20s, it's more likely paying for what he will do, as opposed to what he already has done.
You get what you pay for (usually): One of the basic tenets of free agency held true, mostly, last winter. Often, the best deals come at the ends of the spectrum: either well-selected, inexpensive players on small contracts, or the best players available. It's in between where mistakes are made.
Two of the best-looking deals from last offseason, so far, are two of the biggest. The Tigers' signing of Fielder and the Rangers' acquisition of Darvish both stand out as successes in the short term. Albert Pujols' signing by the Angels looks a little more uncertain so far, but it certainly isn't anything like a disaster at this point.
Elite talents are hard to come by. And as more and more teams lock up their stars, keeping them from reaching free agency (think Evan Longoria, Cole Hamels, Troy Tulowitzki and Matt Cain, to name just a few), fewer and fewer become available on the open market. So when one is out there, it's worth spending to acquire him.
Park effects matter: We've come a long way in understanding and acknowledging the effects that a ballpark can have on a player's numbers, but sometimes it can still be tough to overlook the raw numbers. It's important, though.
The best example of this from last year may be Kubel, who went from a pitchers' park to a hitters' park and saw his numbers explode. As Upton moves from St. Petersburg to Atlanta, he could hit exactly the same and yet see his numbers improve. If Mike Napoli were to sign with the Rays, meanwhile, he'd be going to a much tougher park to hit. It's likely his numbers would decline, even if his skill level didn't.
Matthew Leach is a writer for MLB.com. Read his blog, Obviously, You're Not a Golfer and follow him on Twitter at @MatthewHLeach. This story was not subject to the approval of Major League Baseball or its clubs.