さすが

as one would expect, only natural, that is just like..., even

すごい！さすが先輩せんぱい！

Wow! That's what I would expect from you senpai!

Explanation

「さすが」 has 2 uses

Living up to a reputation, which impresses you: 「さすが専門家だ」 (that's an expert for you), 「さすがの神戸牛」 (Kobe beef, as you'd expect).

いいカーブだ。流石さすがダルビッシュ。

What a nice curveball. That's just like Darvish.

すごい！さすが先輩せんぱい！

Wow! That's what I would expect from you senpai!

Mostly 「さすがに」「さすがの〜も」: even the toughest give in when things go too far: 「三日も徹夜すると、さすがに体がもたない」 (three all-nighters is too much for anyone).

流石さすがに今日きょうは雨あめが降ふりすぎだろ...

It's really raining way too much today...

さすがの君きみでもこの問題もんだいは難むずかしいだろう。

Even for someone like you, this problem is difficult, isn't it?

Examples

1Just as you'd expect

さすが田中たなかくん！発注はっちゅうミスの天才てんさいだね！
Tanaka-kun, you never fail! A real genius at ordering mistakes!
いいカーブだ。流石さすがダルビッシュ。
What a nice curveball. That's just like Darvish.
一流いちりゅうのオーケストラの演奏えんそうは流石さすがですね。
The performance was as would be expected from a first rate orchestra.
涙なみだが出でるほど夕焼ゆうやけが綺麗きれいだ。流石さすが神様かみさまだ。
The sunset was beautiful enough to elicit tears. As one would expect from the gods.
会話かいわが漫才まんざいのようだ。流石さすが関西かんさい人じん。
The conversation was like talking with a comedian. That's just like a person from Kansai.
流石さすがの神戸牛こうべぎゅうだ。世界一せかいいち脂あぶらの乗のった肉にくだ。
As one would expect from Kobe beef, it has the best marbling in the world.
流石さすがに空手からての稽古けいこを積つんできただけに、１５ｋｇのダンベルは持もてる。
As might be expected from a person who trains karate, he can lift 15kg dumbbells.

2Even so, too much

さすがの君きみでもこの問題もんだいは難むずかしいだろう。
Even for someone like you, this problem is difficult, isn't it?
流石さすがに今日きょうは雨あめが降ふりすぎだろ...
It's really raining way too much today...
流石さすがに食くいすぎたな。椅子いすから立たてない。
I really ate too much this time. I can't get up from the chair.
こんなおめでたい席せきに、流石さすがにあの格好かっこうはない。
Dressing like that for such a happy occasion is really too much.
流石さすがに落おとし物ものが多おおすぎる。注意ちゅういしないと。
There really are too many lost items. I need to be careful.
指圧しあつのしすぎで、流石さすがに親指おやゆびが痛いたい。
I've given so many shiatsu massages that even my thumbs hurt now.
流石さすがの君きみでも、あれだけ食たべればカロリー取とり過すぎです。
Even for you, eating that much is too many calories.
流石さすがの解説者かいせつしゃも、今日きょうの試合しあいの結末けつまつは予想よそうできなかった。
Even (an established) commentator couldn't have predicted the ending of today's match.