The top-lock is a less frequent pindown defense mostly reserved for wide pindowns or staggers out of the corner. Whereas the lock and trail encourages an offensive player to use an off-ball screen, the top-lock does the exact opposite: It forces the player away from it. In practical terms, this means a backdoor cut.
当b球员给a球员进行掩护的时候，防守者的站位是为了防止射手借助b球员的掩护兜出来接球跳投，所以当防守者为top lock站位时，a球员要利用backdoor切入篮下，寻找防守漏洞，
