Is this an appropriate f6 break?

The move 6...Bd7 is incorrect.
White is said to get a good position after 7.dxc5!
The correct move is 6...cxd4
The line white is playing is the Milner-Barry Gambit.
It gives up the d4 pawn for tricky traps & deadly attacks.
However, if black can find his way through the maze he often ends up in a better position.
If you want to learn more about how to play the black side of the Milner-Barry Gambit.
I suggest you read the following forum:
https://www.chess.com/forum/view/game-analysis/short-game-what-was-wrong
The OP of that thread asked about the Milner and I went into more detail in that forum!
You might find it informative/instructive!

Is this an appropriate f6 break?
To answer the above title of your forum.
The answer is No!
Against strong players black will not be able to achieve the f6 break here.
Simply because white will continue with 7.dxc5 exploiting your move order.
To answer the above title of your forum.
The answer is No!
Against strong players black will not be able to achieve the f6 break here.
Simply because white will continue with 7.dxc5 exploiting your move order.
Can you go into more detail with your answer? You just say for both examples white plays dxc5 and exploits move order or gets a good position but you don't explain why.
- Yes, your 7...f6 is a good move. Actually second best after 7...cxd4, which tries to take advantage of the bishop placement at c2. 8.exf6?! Nxf6 is very comfortable for Black.
- 7.dxc5 is a more principled answer. But 6...Bd7 is light years away from "incorrect". French expert GM Keith Arkell playing Black and willingly going for that position:
Just a small tip: When in doubt about a move, ask X_PLAYER_J_X.
Then, do the exact opposite from his advice. You have very good chances to play the correct move!
Thanks for clearing it out, I was very confused from X_PLAYER_J_X's response haha.

Thanks for clearing it out, I was very confused from X_PLAYER_J_X's response haha.
Truthfully, Jeremy I wouldn't listen to Pfren here.
Pfren has a habit of trying to prove me wrong even at the expense of recommending inaccurate lines!
GM Keith Arkell has played that position longer than anyone.
7.dxc5 is said to be good for white.
Keith Arkell doesn't care!
Keith Arkell has played the black position for so long!
People would be scared to play 7.dxc5 against him!
Simply because he knows the position very well.
The truth is none of us may ever be able to play the position as black like Keith Arkell.
Which goes to say you shouldn't try to play that way.
The main reason 7.dxc5 is considered the move to play as white is based on the idea of white being able to make use of the d4 square.
White often trys to use the square as an outpost square.
One very common way they do this is with following moves.
After black moves away the dark bishop.
White can at any point play Be3 with tempo on the black queen. Once the queen moves off b6 white will be in a prime position to use the d4 square as an outpost!
If you look at GM Keith Arkell game he played the move 8...a5 trying to prevent b4!
At move 9.Nbd2 white is threaten to play Nb3 to attack the dark bishop away to get it to move.
As you can see white wants the dark bishop to move so that when they jump into d4 black can't exchange off a bunch of pieces!
In response to 9.Nbd2 black had to continue with 9...a4 which prevents Nb3!
Needless to say GM Keith Arkell knows what he is doing in this position!
White and Black are both fighting for d4 in this game.
Truthfully, I think trying to play this position is a bigger headache than playing the normal way!
Have you ever heard the chess phrase "The only sound gambit in chess is the Queens Gambit!"
The Opening name of white is a dead give away!
White is playing Milner-Barry Gambit!
This line is not considered the best way for white to play against the French!
It has issues!
It is tricky & attacking.
However, if black finds his way through the maze they are often better if not winning!
@ XPlayer
Why not just argue that 6...Bd7 is unplayable because 7. dxc5 Bxc5 8. O-O Nce7? 9. b4 Bxb4 10. cxb4 Qxb4 11. Ba3 offers Black insufficient compensation?
Your argument is that the line should be avoided because only one particular grand master can find meaningful moves in the position. Your argument ignores that anyone viewing this forum can see the game Pfren posted and knows what there meaningful moves are. It also lacks a factual underpinning because I deny that Keith Arkell's ability to play this position is unique.
So, if you come forth with proof that GM Arkell's is the only person able to find the a4-a5 plan, and that the a4-a5 plan is unlernable by normal means, then your argument will be correct. But since you obviously can't do this, why not just post bad moves?

To be fair for a longtime 6...Bd7 was considered inferior because of a game of Nimzowitch, which is so famous forget who his opponent was, but it is in databases. The game is explained in "My system" I think. Don't think the opponent played a5 though... Even with a5 it looks somewhat dangerous for black.
This is similar to Botvinnik v Capablanca in the Nimzo, which established that the pawn formation in that game is dangerous for black, for sometime. Then years later Anand v Carlsen happens which shows it playable afteral. All the same not sure many club players could have defended black's position.

@ XPlayer
Why not just argue that 6...Bd7 is unplayable because 7. dxc5 Bxc5 8. O-O Nce7? 9. b4 Bxb4 10. cxb4 Qxb4 11. Ba3 offers Black insufficient compensation?
Your argument is that the line should be avoided because only one particular grand master can find meaningful moves in the position. Your argument ignores that anyone viewing this forum can see the game Pfren posted and knows what there meaningful moves are. It also lacks a factual underpinning because I deny that Keith Arkell's ability to play this position is unique.
So, if you come forth with proof that GM Arkell's is the only person able to find the a4-a5 plan, and that the a4-a5 plan is unlernable by normal means, then your argument will be correct. But since you obviously can't do this, why not just post bad moves?
Posting bad moves to have people agree with your argument is not my aim!
People who do things like that are people like Pfren.
I think the OP should make the decision on which line he likes based on his own weakness & strengths in chess!
I simply am trying to state information!
So he can make a reasonable decision.
Plus I will tell him my own personal choice.
Incase he wishes to know!
I think the OP should see good moves.
By seeing good moves he can understand more clearly!
Keith Arkell's ability to play this position is not unique!
However, what is unique is Keith Arkell's playing experince in this particular line!
He has been playing it forever!
I showed some good moves a4 - a5 simply showing how white is trying to threaten to move the dark bishop away.
I showed how black trys to prevent them from moving it away!
You can see how a struggle ends up happening!
All of these things are due to the fact you saw some good moves!
And by seeing this good moves you now understand your choices better!
A) Play this line were you may end up in a struggle for the control of d4!
B) Play against the mainline Milner-Barry Gambit were you can be up 1 pawn. However, you will of course have to find your way through the maze.
C) Play a different variation of the French!
D) Play a different line vs 1.e4!
Those are the OP's options!
I personally like option B.
I am materialistic!
I like calling my opponents bluff!
I like trying to hold fast!
I would take the d4 pawn, slap my opponent around, and tell him to do his worse!
If it was an OTB event I would start yelling "Show me!"
Show me!
Show me!
Show me! Your compensation for the loss of that pawn you son of a bish!
I am completely destroying you in this position!
However, That is my own person choice aggressivesociopath!
Some people have picked different letters!
Keith plays option A
Some people play option C
The French Defense/Advance Variation/Wade Variation
Some people play option D
The Sicilian Defense - Kings Pawn Game - Caro-Kann
The OP & chess community have tons of options!
Which one will they pick?
Who know's!

What is all this stuff about Keith Arkell being an expert in the French defence. He predominately plays the Caro-Kann and thus is known for his expertise in this.
In terms of the best move at move 7 is it not cxd4 followed by Nb4?

What is all this stuff about Keith Arkell being an expert in the French defence. He predominately plays the Caro-Kann and thus is known for his expertise in this.
In terms of the best move at move 7 is it not cxd4 followed by Nb4?
Keith Arkell is a Grand Master he knows several lines very well.
You kind of have to know more than one line at that level.
However, the best move for black happens at move 6.
Black should play 6...cxd4.
Those are the most theoritical moves.
At move 9 the main move white has been playing is 9.Nxd4.
However, I do think a new move has been tryed 9.Nbd2.
It probably is a sideline of sorts.
I don't know a lot about it to be honest.
However, 9.Nxd4 has been the main move in that spot.

@repac3161
In terms of the best move at move 7 is it not cxd4 followed by Nb4?
If you are asking this question on the bases of the OP game with out white or black playing good moves than your answer is yes!
However, This position will never happen if white or black play correctly.

Regarding the Rubinstein. Just because is good enough it does not mean it's good for everyone. It can be employed in case of both Nd2 and Nc3, that's the good part, but it's not sharp enough for one and only reason, there are no substantial weaknesses on both sides, of any kind.

Chess 101: It is better to attack a pawn chain at the base when possible.
7...cd should be played here.

5... Bd7 was mentioned by Greco as early as 1620, and was revived and popularised by Viktor Korchnoi in the 1970s. Now a main line, the idea behind the move is that since Black usually plays ...Bd7 sooner or later, he plays it right away and waits for White to show his hand.
If White plays 6.a3 in response, modern theory says that Black equalises or is better after 6...f6! The lines are complex, but the main point is that a3 is a wasted move if the black queen is not on b6 and so Black uses the extra tempo to attack the white centre immediately.

5... Bd7 was mentioned by Greco as early as 1620, and was revived and popularised by Viktor Korchnoi in the 1970s. Now a main line, the idea behind the move is that since Black usually plays ...Bd7 sooner or later, he plays it right away and waits for White to show his hand.
If White plays 6.a3 in response, modern theory says that Black equalises or is better after 6...f6! The lines are complex, but the main point is that a3 is a wasted move if the black queen is not on b6 and so Black uses the extra tempo to attack the white centre immediately.
a3 f6 Bb5, probably best for black is fe5, what follows is Bxc6 bc6 followed by Bg5 by white ∞