noun
keystone combination
Abbreviation of 'keystone combination'; refers to the shortstop–second baseman duo in baseball, considered the core of the infield defense.
あのチームのキーストーンコンビは鉄壁の守備を誇る。
That team's keystone combination boasts an ironclad defense.
Refers to the area between second base and shortstop, or the players themselves; more common in Japanese baseball commentary than the loanword キーストーンコンビ.
Variant with interpunct, sometimes used for clarity.
From English 'keystone combination', abbreviated in Japanese baseball terminology.