Practicing with ところで

Hello, fellow members. こんにちは、全員。This my first post so sorry if it is flawed in some way. これは初めてpostなので悪かったらすみません。I studied about ところで when used with the plain past form of verbs. It is supposed to be used to state the speakers prediction about something and it has a negative nuance to it. So I guess is mean, roughly, "despite" or "even if" Below are a few sentences using it. Any advice is greatly appreciated. 本当にありがとうございます。
今僕は家を出たところで彼女を助けられない。Even if I leave now I cannot save her.
君はこれを買ったところで価値が上がらない。 Even if you buy this it will not rise in value.
あいつは質問が分かったところで答えなかった。 Even if he understood the question he did not answer.
よろしくお願いします。

～たところで has many meanings/functions. For instance, 今家を出たところで can be interpreted also as "ところ as the moment + で for the continuous usage of the -te form of copula", i.e., ちょうど今家を出たところだから because I've just left home. If you want to use ところで as "as if" in those sentences, you need to make the meaning clearer, using たとえ or もし. Also, ～たところで as "even if" is a conditional clause, so the subject marker must be が. When は is used, the subject of the main clause must be the same as the one of the subordinate clause.
I would say;
たとえ僕が今すぐ家を出たところで、彼女を助けられない。
たとえ今すぐ家を出たところで、僕は彼女を助けられない。

君がこれを買ったところで、価値は上がらない。
(君は can't be used here since the subject of the main clause is not 君.)

あいつは、たとえ質問が分かったところで、答えなかっただろう。

～ても or ～としても is more common and natural for all these cases.

Thanks for the help.
I have not covered たとえ もし so I am not sure of their usage, but I think I understand what you are saying. The main clause,which is the second one, has to have the same subject to use は, and the first part, the sub-clause takes が to mark the subject.
I have covered ても and I sounds the same to me. I know there must be a nuance difference, but I am just not sure what it is. Can you explain the difference between ところで and ても, please.
Just for the sake of making sure I understand ところで I am going to write a couple sentences.
タコさんが勉強したところで、試験が通らない。Despite Taco's studying he will not pass the test.
君が早く出社したところで、部長が君と会えない。 Even if you leave early the boss cannot meet you.
I truly appreciate your help. どうもありがとうございます、トリトリべさま。

Zuba said:

Can you explain the difference between ところで and ても, please.

Click to expand...

The meaning is basically the same. ところで is more written-language-like.

～たところで is a conditional for contrary-to-fact (反事実), thus, 勉強したところで implies that he actually won't study. You can't use this structure when he really studied. Instead, ～にもかかわらず or ～ようが～まいが is used in those cases.

勉強したにもかかわらず/勉強しようがしまいが、タコさんは試験に通らないだろう。
Despite Taco's studying, he will not pass the test.

タコさんが勉強したところで、試験に通らないだろう。
Even if Taco studies, he will not pass the test.

君が早く出社したところで、部長は君と会えない（だろう）。

THANK YOU! This really helped out a lot! どうもありがとうございます。