Benko Gambit vs. Blumenfeld Gambit

Cambridge Spring very passive?

I prefer Benko

according to the computer b5 is blacks best option

Thanks for the bump

i mean according to the computer white is only +.5

compared to the benko which is +1.5

the blumenfeld's compensation is similar to the Na5 line in the knight attack

would you say that is true?

black is just more active it seems

My idea was that Benko (when it works) generally leads to a positional game and Blumenfeld (when it works) leads to an aggressive tactical game.

I dont know the current theory of either (haven't player either since the 1970's). When I studied Blumenfeld it was from a tiny, quite old pamphlet in Swedish. When I studied Benko it was from Benko's book where everything was a forced win for black. (In summary, ignore anything I say about theory of either.)

At my level I wouldn't expect my opponent to be super booked up on either and would choose based on what kind of game I felt like playing at the moment.

polerio defense i think is its name

I think the The blumenfeld gambit is stronger when white plays it (Into the move sequence that leads to a reversed blumenfeld gambit which is 1. nf3 d5 2. c4 d4 3. e3 c5 4. b4). However i still think it's decent for black as, if accepted, black gets a very good center. 
As someone said, benko is more positional play and blumenfeld is also positional, but more agressive

I am trying the blumenfeld out.

I need something new against d4.

Thanks!

I regularly emploxy the benko (mainly otb games) and I find it to be a bit tactical, yes, but its strengths lie in positional setups with the major pieces. White has to be prepared as to not lose the entire queen side, when the black c pawn might become decisive...

However, It is still not an easy win, and you must be prepared with middle and end game knowledge to use it.

Both are decent, but I would rather play the blumenfeld than the benko gambit for a few reasons.

1. The benko gambit is one of the most common gambits against d4 and all d4 players should be prepared for it.

2. There are ways to play against the Benko gambit that avoids complications and aim for a more positional game. For example the "quiet line" with 4.Nd2. Although not the best way to play for white, in this variation, it is still white that dictates the direction of the game, which is not usually what the gambit player looks for.

3. If everything fails there is no winning back the pawns sacrificed - which can always be a bonus in any gambit.

4. From what I know, there is not a simple way to refuse the complications of the Blumenfeld. 5. cxb5 looks horrible for white, 5.Bb5 a6 6.Bxf6 Qxe6 looks better for black.

5. The Blumenfeld is relatively unknown and not every d4 knows what to play against it.

6. If everything fails, there is always a weak b5 pawn that usually is not that hard to win back.

7. If a white players play the following line: 1. d4 Nf6 2. c4 e6 3. Nf3 he usually does so to avoud the theory-heavy nimzo lines, expecting solid positional play. In other words, most players that play this way, does not want to face the Blumenfeld.

Your choice. Blumenfeld is GENERALLY more fun such as

Does dxe6 fxe6 cxb5 d5, FOLLOWED BY a6 ring a bell?

(Also 5. Bb5 is illegal--did you mean 5. Bg5?)