立(た)ち上(あ)がりstart, beginning, build up, how well a pitcher pitches at the start of the game

古(ふる)いパソコンの立(た)ち上(あ)がりは遅(おそ)いです。

The startup of this old computer is really slow.

立(た)ち上(あ)がりが悪(わる)い投手(とうしゅ)を起用(きよう)することは出来(でき)ません。

We can't put in a pitcher who struggles at the start of the game.

好調(こうちょう)な立(た)ち上(あ)がりを見(み)せたチームのサポーターはご機嫌(きげん)だ。

The team had a strong start, and their supporters are thrilled.

立(た)ち上(あ)がりが悪(わる)いこととて、このパソコンはあまり売(う)れていないのです。

Since its startup is so sluggish, this computer hasn't been selling well.

その選手(せんしゅ)は立(た)ち上(あ)がりが悪(わる)いが、ウォーミングアップをサボっていたのだろうか？

That player had a rough start. Maybe he skipped his warm-up?