hammer out

米大リーグ，マリナーズの岩隈仁志投手が同球団との契約を2年延長することが決まりました。簡単な表現ではありますが，一つ取り上げさせて頂きます。hammer outはcome to agreementなどと同様に「合意」を表す表現です。裁判の判決に用いられるハンマーが想起されます。辞書で確認してみるとhammer out「（苦心の末に議論や意見の相違などを）解決する」とありました（『新英和中辞典』，旺文社）。裁判や議会などで議長が裁定したときにふるう木槌（wooden hammer/mallet）から来ているようです。今回の契約交渉期日ぎりぎりで契約の延長が決まったため，この表現が用いられていたのだと思います。（GP）

Iwakuma, 31, would have become a free agent after Saturday if he and the Mariners didn't come to an agreement, but the two sides hammered out a contract that includes an option for a possible third season in 2015. As first reported by Jon Heyman of CBSSports.com, the deal is worth $14 million for two years, with Iwakuma earning $6.5 million in 2013 and '14, with a $1 million buyout on a $7 million option for 2015. Iwakuma originally signed a one-year, $1.5 million base contract with Seattle last year as a free agent out of Japan. He went 9-5 with 3.16 ERA over 30 appearances in his first season in the Majors. He began the year as a long reliever, then transitioned into the rotation midseason and went 8-4 with a 2.65 ERA in 16 starts.
http://mlb.mlb.com/mlb/fantasy/news/#player_id=547874