unless

質問にお答えします。質問内容は以下のunlessの意味合いにつてです。
SURPRISE, Ariz. -- Catcher Mike Napoli counted seven. That is how many different pitches Yu Darvish threw during his third live batting practice session on Wednesday.
Napoli saw a fastball, sinker, curve, slider, changeup, cut fastball and split-fingered fastball. That's pretty much the gamut of pitches, unless Darvish develops a screwball or knuckler.
"Today was the first day I got to see everything," Napoli said. "He threw every pitch pretty good. He threw everything on both sides of the plate."
A pitcher with seven different pitches is almost unheard of in baseball. C.J. Wilson had five pitches, and that was considered excessive.
"Not too many guys have more than four pitches or use more than four pitches in a game," Napoli said. "The game will dictate what we do. He threw a couple of splitters and the bottom just dropped out. He knows how to manipulate the baseball."
http://texas.rangers.mlb.com/news/article.jsp?ymd=20120229&content_id=26912658¬ebook_id=26917116&vkey=notebook_tex&c_id=tex

unlessは「…でない限り，…しない限り」という意味ですが，他にも「…する場合を除いては」などの意味でも用いられます（『ジーニアス英和辞典』第４版，大修館書店）。記事を見ると，今回の投球練習でダルビッシュ投手は持ち球である７球種を投じたことが記されています。それを踏まえると，赤字の部分は「ダルビッシュ投手がスクリューボールやナックルボールの精度を（今後）向上させる場合を除いては，これが彼の球種のほとんど全てだ（これが彼の投球のほぼ全貌だ）。」といった意味がとれそうです。また，unlessとは関係ありませんが，同投手は以前スクリューやナックルを投じたことがあるため，ここではdevelopが使われると思われます。（GP）