Benko Gambit vs. Blumenfeld Gambit

It does seem to be rehabilitated. If, however, that rehabilitation is a recent thing, isn't it likely to be because the holes in some new assumptions haven't yet been found? After all, it was considered to be fine and then someone proposed that white is actually comfortable defending a pawn up and it did seem to be the case. It seems doubtful that this rehabilitation is likely to be permanent.

There's a game of Alekhine crushing someone with it that scared the hell out of me. But of course I'll never face anyone of that level, Blumenfeld or not...

It's hard to make sense of what this question means, since Black isn't the one doing the choosing.  It's White who decides whether to insert Nf3 on move 1 or 2.  There's one Benko declined line (3. Nf3 -- declining even the first pawn, which is fairly infrequent relative to the more common Declined lines where you take the first pawn and decline the second) where Black can choose to transpose to the Blumenfeld. But we're talking about a position where White's made it clear they don't want to play a typical Benko game, so Black is deciding whether, in that circumstance, they want the Blumenfeld lines or some other lines enabled by White's move order.  Since those alternatives offer a pretty good game, they're usually taken, even by players who might choose to play the Blumenfeld if White played 1. d4 Nf6 2. Nf3.  I think there are a few other rarer places where Black can transpose from particular spots in the Benko declined to a specific  line in the Blumenfeld. But one is never forced to choose between the two openings in a general way.

After 1. d4 Nf6 2. c4, you can choose to play the Benko, or not, with 2 ... c5 3. d5 b5. (White has alternatives to 3. d5 but they're infrequent and unimpressive.) After some other move orders, dictated by White, such as 1. d4 Nf6 2. Nf3 c5 3. d5 e6 4. c4, you can choose to play the Blumenfeld, or not, with 4 ... b5.  Nothing precludes making one, both, or neither, a part of your preferred repertoire.

It's like asking if you'd rather root for Bronstein against Botvinnik or for Korchnoi against Karpov.  They're different questions.

benko

It's like asking if you'd rather root for Bronstein against Botvinnik or for Korchnoi against Karpov.  They're different questions.>>>

I'd go for Bronstein against Botvinnick. I once met Bronstein.

Yeah definitely Bronstein - Botvinnik seems interesting

I'd go for Korchnoi against Karpov.  

I once played Korchnoi.

How did you play Korchnoi?????????????????

How did you get on??

It was at a simul at the Manhattan Chess Club in 1970's when I was a teenager.

Wow that must have been very cool- did you draw or win

I lost the game.  I think I played the black side of the Cambridge Springs Defense.

I was invited to play because it was a simul for Juniors, and I was lucky because I hadn't been a member of the chess club for very long.

I also didn't know proper simul etiquette, since I offered him a draw while I was a pawn down.  He shook his head, and I dejectedly dropped my gaze.  My father and brother (standing behind me) said that when he walked away he muttered something and sneered.

Heh. I once played Karpov. 

In fact, to bring it back on topic, I played (and lost) a Benko Gambit. 

That's why you lost ..... Cambridge Springe is very passive. He didn't have a rep. for being the nicest person.

Cambridge Spring very passive?

Well... haven't you noticed that only some very passive players like Carlsen, MVL, Duda, Artemiev, Mamedyarov and Shirov are employing it regularly?   

I prefer Benko

Hi, I confess I made that comment to see if you would challenge it, because I'm genuinely interested in your take on the Cambridge Springs. It was the Defence I employed when learning chess back in the late 80s, when it seemed to be deeply unfashionable. I would play it against younger opponents who might not have encountered it.

My take, for what its worth, is this:

The Cambridge Springs is an unusual, Slav-like method of deployment for black, which ignores the c8 bishop for a while and concentrates on traps. With simple development, white gains a small but useful edge. Sooner or later, black is going to play dc, where white will capture on c4 with the knight, hitting the queen. Thereupon, black has two choices .... passive retreat of the Q and B to try to point them towards white's kingside or a risky venture with the Q, over to the K-side. If white knows what s/he's doing, black is still behind in development. Still has to activate the c8 bishop, after all that. Yes, white has to make sure black doesn't create a dangerous attack, and I've lost once or twice as white when I've overlooked something. But most of the time I find as white that I get the better position combined with better development and black is playing only for a draw.

according to the computer b5 is blacks best option