这则关于篮球比赛的报道有的地方看不明白（1）

这则关于篮球比赛的报道有的地方看不明白（1）
After taking a rest in the second quarter,James returned to the court with Miami trailing 40-38.He muscled underneath for a bucket,hit a pair of free throws and,following Bosh's defensive rebound,connected again during a 13-3 run to take a 51-43 lead.
Bosh said the Heat are still installing their offense.
上边是前两天NBA季前赛热火对雷霆的比赛报道片段.其中有的地方翻译不过来,请朋友们讲解一下.
1.He muscled underneath for a bucket,这句话里有“用力挤”,“在……下面”,“（篮球场的）篮下禁区”,他用力挤到篮下?不知道我翻译的是否准确；
2.hit a pair of free throws and.这句也翻译不出来,而且为什么and在句子的最后呢?
3.connected again during a 13-3 run to take a 51-43 lead,这句话,根据篮球比赛一贯的报道手法我理解出来大致的意思是热火队打出来一拨13：3的小高潮,并以51：43的总比分领先.但是其中的connected again during我翻译不好,根据字面意思翻译不出来一句像样的话.
4.Heat are still installing their offense.这句话中install,offense有什么引申义么?