I want to ask about the use of (으)로 in the baduk (Go) book I'm reading now (이창호 타이틀 명국집2). The numbers (e.g. 백50) refer to the moves as they are labeled on the diagrams in the book.
I'm used to the following kind of (으)로 which can easily be translated as 'with':
(1) 백50 이하는 56으로 공격하기 위한 대담한 작전인데 부분적으로는 손해다. (p.39)
'[The moves] after White 50 are a bold strategy in order to attack with White 56, but are a loss locally.'
What I'm not sure about is the use of (으)로 in the following examples which comes up when the book suggests alternative moves. The translations are my current best guess.
(2) 흑37은 느슨한 수로 A의 곳이 컸다. (p.42)
'Black 37 is a loose move and [a move at] A would have been bigger'
(3) 흑73이 敗着으로 4도 흑1이 대세의 급소였다. (p.39)
'Black 73 is the losing move and Black 1 in Diagram 4 was the critical point.'
Are these the same usage of (으)로 as in example (1)? They don't seem easily interpretable with 'with', though. Translating them as 'and' as I did above makes sense semantically and fits with what the book is doing (commenting on the bad move and then suggesting an alternative), but is this a usage of (으)로? I haven't seen this before.
In short, how should we interpret the (으)로 in examples (2) and (3)? Thanks.