You got it.

官網規則
A save is a statistic credited to a relief pitcher, as set forth in this Rule 10.19.
The official scorer shall credit a pitcher with a save when such pitcher meets all four of the following conditions:
(a) He is the finishing pitcher in a game won by his team;
(a) (他是勝隊最後一個投手)

(b) He is not the winning pitcher;
(b) (他不是勝利投手)

(c) He is credited with at least a third of an inning pitched; and
(d) He satisfies one of the following conditions:
(他至少投 1/3 局, 且符合下列情況的一項)

(1) He enters the game with a lead of no more than three runs and pitches for at least one inning;
(1) 進入比賽時, 領先不超過三分, 至少投完一局.

(2) He enters the game, regardless of the count, with the potential tying run either on base, or at bat or on deck (that is, the potential tying run is either already on base or is one of the first two batters he faces); or
(2) 進入比賽時, 不管比數多少, 追平分在壘上, 或在打擊區, 或在準備區 (就是說, 追平分在壘上, 或是他將面對的下兩位打者)

(3) He pitches for at least three innings.
(3) 他至少投三局.

今天 Rivera 要符合救援成功, 的確需要兩人在壘上