Two baseball teams just collectively made the toughest and most fraught decisions of the winter. It's been a while since the New York Yankees let a homegrown superstar leave for more money -- and, for that matter, since the Seattle Mariners made such a big, and risky, splash.

Second baseman Robinson Cano has agreed to a 10-year, $240 million contract with the Mariners, as ESPN first reported. This is an enormous deal, of course, one of the largest ever -- in terms of total dollar value, below only Alex Rodriguez's, and tied with Albert Pujols', now two rather chilling names for Mariners fans -- and like just about any 10-year contract given to a player over 30, it will likely turn into a ball and chain by the end. At the same time, the Mariners got themselves the best free agent available by a wide margin, a player comfortably on a Hall of Fame track, and also the best the market is likely to see for a while, given the current trends. They outbid the Yankees' last reported offer by about three years and $65 million.

Until Thursday evening, it was widely assumed that Cano would end up back in New York. The Yankees have the money (or anyway would, were they not seemingly so determined to stay under that $189 million line), he seemed to want to stay, and until Seattle emerged late, there were no other obvious destinations for Cano. Not since Andy Pettitte went to Houston after the 2003 season have the Yankees let a star they'd developed walk. But Pettitte was going home to Houston to play with his friend Roger Clemens, and while beloved by New York fans, he was not the player that Cano is -- he was a very good pitcher, but Cano is the best second baseman in baseball. Bernie Williams, Mariano Rivera, Derek Jeter, Jorge Posada -- all of them at one time or another flirted with leaving in free agency, but when push came to shove, the team did what was necessary to keep them.

Cano's deal is huge, yes, but it was always going to be huge, making the Yankees' statements about absolutely not going to $200 million or more for him seem oddly hardline. Only Joe Morgan and Rod Carew consistently hit as well or better while playing second base in the modern era; he has played nine seasons, eight of which were good-to-great, and he hasn't missed more than three games in a season since 2006. In this market, that means you've earned yourself a crazy deal. It's possible that he'll even be worth it, or nearly so, even expecting the inevitable decline with age.

(Sidenote: There has been this idea throughout the process that Cano's agent, Jay Z -- despite many years of success in diverse business endeavors, and despite partnering with long-established talent agency powerhouse CAA -- was somehow stumbling along over his head in the sports world, miscalculating, blowing things for his client, not like Scott Boras would have done, as if Boras never asked for insane amounts of money with varying results. Most of the people who suggested these things would likely not last a week in the music industry without being eaten alive, and hopefully this contract puts an end to that canard.)

Did the Yankees really think they were going to get Cano for less than $200 million? It seems that either they drastically underestimated his worth, or they were never serious about retaining him in the first place, and just made a bit of a show for the sake of the fans. You might expect loyalty to a team or affection for a city to get you a bit of a discount, but surely they didn't think it would -- or should -- save them $65 million.

While giving 10 years to a 31-year-old is inherently very risky, Cano would seem to be about as safe a bet as you'd find for it, between his consistency and his durability. By contrast, the Yankees' two big free-agent signings this offseason -- both arguably overpays, though on a smaller scale -- were both riskier in their own ways. Brian McCann, while consistently good and just 29, is a catcher, and therefore likely to accumulate significant wear-and-tear and possibly move positions at some point over the course of the deal. He signed for five years and $85 million. Jacoby Ellsbury is an excellent outfielder but has struggled with injuries and consistency throughout his career, and at 30, has put together only two seasons that were both healthy and very good; the Yankees signed him for seven years and $153 million. Choosing to splurge on him is not an odd move for New York; but choosing to splurge on him at the expense of Cano is surprising.

Of course, Alex Rodriguez and Albert Pujols (the latter of whom, to be fair, might still bounce back) were also thought to be relatively safe bets for a huge long contract, and Cano, for all his skill, is not the player either of them were when they signed their deals. Perhaps the Yankees concluded that they could handle anything for a few years, but were determined to retain more flexibility that they have in the past, to avoid the chance of another Rodriguez-like burden. That's certainly understandable, but if that's the case, were their grudging contract negotiations with Cano's camp over the last few months really in good faith?

We won't know for a long time whether this deal is really "worth it" for Seattle, though certainly after suffering through a .225/.303/.382 season from second baseman Nick Franklin last season, Cano will be not just a breath but a gale of fresh air. In the end, whether the contract works out will depend on much more than just Cano's performance -- it will depend on the players they surround him with. Between Cano and Felix Hernandez, the team has two huge and valuable stars, but also a long way to go. They do not, for example, have anything resembling a major league outfield. They also need another pitcher. Will they get those things this offseason? Sign Shin-Soo Choo, trade for David Price, figure something else out?

If they don't land several other additional pieces, and choose them wisely, then the Mariners have a rough road ahead. That road now features a lovely view of Cano's smooth, strong swing, but as the Yankees and their fans saw last season, there's only so much that can accomplish by itself. And Robinson Cano would be a terrible thing to waste.