The offseason's most anticipated free agent will join the New York Yankees after a long winter of speculation and new rules for signing Japanese baseball players.

Masahiro Tanaka agreed to a seven-year, $155 million contract with the Yankees, including an opt-out clause after the fourth year. Under the new posting system between Major League Baseball and Nippon Professional Baseball, New York also owes a $20 million posting fee to Tanaka's former team, the Rakuten Golden Eagles.

Tanaka's numbers in Japan speak for themselves -- 24-0 with a 1.27 ERA last season -- though scouts differ vastly on whether he can achieve Yu Darvish-style success in the U.S. or will turn out to be more like the disaster that is Daisuke Matsuzaka. His signature pitch is an upper-80s splitter that drops out of the zone and makes hitters look foolish, with a hard slider and a 92 to 96 mph fastball completing his arsenal. His ability to maintain control and velocity deep into games benefits a Yankees team that will have to adjust to life without Mariano Rivera and transition David Robertson into the closer role. Last season, Tanaka pitched 212 innings, more than any other starter in the Yankees' rotation.

The move effectively ends Hal Steinbrenner's dream of coming under the league's $189 million salary cap, a goal most analysts thought (and most New York fans hoped) was unrealistic. After losing infielder Robinson Cano to the Seattle Mariners, the Yankees have spent almost half a billion dollars to avoid a repeat of last season, in which the team not only missed the playoffs for only the second time in 19 years but also had to watch the Boston Red Sox win the World Series and listen to a bunch of talk that the Los Angeles Dodgers were MLB's new big spenders. Anyone who was around in 2008 shouldn't be surprised by the huge number the team offered a player who has yet to pitch in the majors -- when the Yankees have a problem, they throw money at it.

Where the Tanaka signing differs from the Yankees' familiar pattern is his age. Unlike when they signed Kevin Brown and Randy Johnson -- overpaying for aging stars, sacrificing their future for a quick fix -- the Yankees tied up Tanaka at just age 25. His long-term durability is a question mark, but the Yankees had to gamble that he'll remain healthy through age 32. Assuming the newly svelte C.C. Sabathia can return to ace form, Tanaka is a legitimate No. 2 starter, providing a much-needed boost to a rotation rounded out by Hiroki Kuroda, Ivan Nova and, most likely, David Phelps.

The Yankees have most likely ended a winter shopping-spree enabled by loss of Cano's contract and the bone MLB threw them with Alex Rodriguez's yearlong suspension. And it's ended on a high note, giving fans renewed hope for a well-rounded squad poised for a much better season in 2014. The Tanaka experiment is worth conducting for a team that's used to making headlines for signing big contracts rather than missing the playoffs.

(Kavitha A. Davidson is a Bloomberg View columnist who writes about sports. Follow her on Twitter at @kavithadavidson.)