what does 塞翁 mean in 塞翁失马?
Baidu Baike has character by character explanation:

塞：边界险要之处；
翁：老头：老人。
塞翁：边塞的老头儿。

The explanations of you found is correct, and &quot;塞翁&quot; means an old man living in a tactical border position.