～ばわかる as an idiomatic expression meaning something like "if you do this you'll know right away"

Question

I was playing Genshin Impact just now, and heard the line:

別に考えなくても。。見れば分かるじゃないか

This is after someone says something like "Why are you in Liyue? Is it for the Lantern Rite festival?"

Literally, this sentence is something like "Even if you don't really think about it, if you look you can tell right", or I think the natural translation is something like "I mean that should be plain to see".

What I'm specifically wondering is if this ~ばわかる or maybe 見れば分かる is a particular idiomatic expression to express something that should be obvious if one were to look.

Edit:

Specifically, what happens if we change this to something like 見ると分かる、見たら分かる、見るなら分かる. Intuition tells me the first is fine, the second is weird, and the third is very weird.

Also, I still struggle to understand when exactly ば is used over the other conditionals but one of the usages seems to be in more set phrases, like ～ばよかった or ～ば～ほど, so I'm wondering if this is one of these set phrases or common phrases.

Answer 1

Literally, this sentence is something like "Even if you don't really think about it, if you look you can tell right",

I think you're right.
_{It could also be read as two separate sentences: 「別に考えなくても（いいだろう）。。」+「見ればわかるじゃないか。」, "You don't really need to think.. If you see you can tell, right?" When saying 「(別にetc.) Vなくてもいいだろう・いいでしょう。」, the 「いい～。」 part is often left unsaid in daily speech.}

Specifically, what happens if we change this to something like 見ると分かる、見たら分かる、見るなら分かる. Intuition tells me the first is fine, the second is weird, and the third is very weird.

「見ればわかる」 is often contracted to 「見りゃわかる」 in informal/rough speech (れば→りゃ) eg. 「見りゃわかんだろ！」. 「見ればわかる」 in your example could be rephrased 「見たらわかる」, but 見たら～ may sound more casual/informal than 見れば～, and I think we use 見たら～ more in Kansai (or west Japan) eg. 「見たらわかるやん。」.「見るとわかる」 is grammatically correct, but acceptable in a different context. 「見るならわかる」 sounds unnatural.

What I'm specifically wondering is if this ~ばわかる or maybe 見れば分かる is a particular idiomatic expression to express something that should be obvious if one were to look.

Also, I still struggle to understand when exactly ば is used over the other conditionals but one of the usages seems to be in more set phrases, like ～ばよかった or ～ば～ほど, so I'm wondering if this is one of these set phrases or common phrases.

The phrase is commonly used to say something is obvious, or to say "Can't you see?", but I'm not sure it's an idiomatic expression (慣用句?).

これらの「～ば + (potential) verb」と同じ用法かな、と思います：

「来ればわかるよ。」「読めばわかる。」「勉強すれば受かる。」「申し込めばもらえます。」「煮れば食える。」...
_{「来たらわかるよ。」「読んだらわかる。」「勉強したら受かる。」「申し込んだらもらえます。」「煮たら食える。」とだいたい同じ意味です。（但し、過去形にすると意味が変わると思います。）}

Answer 2

Specifically, what happens if we change this to something like 見ると分かる、見たら分かる、見るなら分かる. Intuition tells me the first is fine, the second is weird, and the third is very weird.

Translated, everything (〜と、〜たら、〜ば) is "if", but actually all japanese conditionals have an inherent nuance. Some nuances overlap, so in some cases they are effectively the same, but in some cases they don't.

〜と usually expresses a logical/natural result because it's constant, repeatable.

eg: ボタンを押すと機械がオンになる。 -> if you press the button, the machine turns on.

〜と is also used to describe habits. More akin to "when" than "if".

eg: 毎日起きると、窓を開く。 -> I open the window everyday when I wake up.

Another use of 〜と is to describe things that simply happened after the first part. Also akin to "when" rather than "if"

eg: 昨日学校に行くと、誰もいなかった。祝日だと忘れた！ -> When I went to school yesterday, there was nobody. I forgot it was holiday!

〜たら can be used in this same fashion (to describe things that simply happened after)

昨日学校に行ったら、誰もいなかった。祝日だと忘れた！ (same meaning)

〜ば is to describe things that are the common outcome, and using it sounds kinda proverb-ish.

eg: 練習すれば、うまくなる -> If you practice, you become good. (But proverb-ish: He who practices, good becomes. or whatever haha)

It's pretty common that people that practice get better, but by no means it's written in stone. Which brings us to the next nuance, related to your sentence.

〜ば is used for hypotheticals. What is considered hypothetical is very subjective, it often depends on how the speaker perceives the condition to be.

An easy example is: 明日雨が降れば、試合が中止になる。(If it rains tomorrow, the match will be cancelled) You can't know whether it will rain or not for sure. In english, an announcement would likely be worded "in the event of rain, the match will be cancelled" for the same reason, it's an hypothetical situation.

So the japanese speaker decides whether to use 〜ば or not, in subjective fashion.

A common phrasing for proposing marriage is "私で良ければ、結婚してください". "If I am good (enough for you), marry me please"

Why 〜ば？ Because the person proposing can't know for sure if their partner consider them "good enough" or not. So -from the speaker point of view- it's an hypothetical situation.

This is exactly what happens in your sentence: "見ればわかる"

If you look (In the hypothetical case that you look) you would know. The speaker can't know if the listener had looked or not nor if they will look or not.

Hence the usage of 〜ば。

BUT! This usage is kind of sarcastic. Which is pretty much the most common usage of 見ればわかる. It sounds hypothetical and proverb-ish... but it's just implying "why don't you just look?".

A somewhat decent summary of conditional nuances and common usage can be found in the following link: http://www.coelang.tufs.ac.jp/mt/ja/gmod/contents/explanation/083.html

Sadly it's only in japanese.