In this strike-out game, you have to throw the balls and see how many stick.
In this strike-out game, you have to throw the balls and get as many to stick as you can.
「ボールが何球くっつくか」＝ how many balls stick (to ～）
「ボールを投げて、何球くっつくかが勝負のストライクアウトゲームです。」＝ In this strike-out game, you have to throw the balls and see how many stick. / In this strike-out game, you have to throw the balls and get as many to stick as you can.
ボキャブラリー
球 ＝ ball
投げる ＝ throw/pitch(野球の場合）
何球 ＝ how many balls
くっつく ＝ stick (to ～)
イギリス 
