Help me prepare for an important club game vs English opening

Even if all the opening prep accomplished was to make you feel a bit more confident, that's still worth something.

I don't pay much attention to evaluations by bots, unless they can show me a specific line.

Bots are great at tactics, but they suck at positional evaluation.

The Opening was an Anglo-Dutch (ie: English => Dutch), not a Dutch "proper". Although since it falls into the A-10 opening classification, I personally would call it a Warthog.

That endgame looks a win to me  - you have more reserve tempi. For example h5 now for you and white has to let your king in.

I wonder whether you could have played the thematic f4 earlier before white played it himself ?

If black play41. ....  h5!!!!!

he will win

What exactly is wrong with 11. ... f4?

11. ... f4 12. gxf4 exf4 13. Nxf4 looks ??? after Bg5.

11. .... f4  looks fine for black.

Yeah white is completely lost after h5.

thanks for the quick analysis - raises some interesting questions for me in how I understand the dutch generally actually - on 9...be3, where you suggest f4 instead.. that sacrifices a pawn after gxf4 exf4, bxf4 - is that okay? I often want to make that push as a sac to open up my rook and start an attack but I'm never sure if its a good idea or not so I tend to play it safe

11... Bf6 - my plan had been Bg5 but once the time came to actually play it I started to worry about tactical problems later on, as its only defender would be the queen. Probably there was nothing to worry about and I was just seeing ghosts. Regardless, I can't now explain why I decided f6 was a better square for it, as it does look incredibly awkward!

I've looked at this game with a computer and it thinks I'm way ahead in the endgame - but its somewhat confusing as the evaluation clearly thinks white cannot keep me out of the b4 square, and I was certain at the time (and more certain now) that the instant my king arrives in that square, I win the game. The engine is so convinced it can't stop me from going there that its top suggestion in the final position after 41... h5 is Kd3, effectively conceding the game on the spot - I can't say I really understand WHY it wants to do this, but it clearly feels the position is impossible to hold. 

for what its worth, stockfish hates 9... f4 - thinks it just loses a pawn.. this doesn't entirely put me off it though as computers defend perfectly so I'm quite happy dropping into -1.xx evaluations if it gives me attacking chances, esp as I can out-calculate a lot of the opponents at my level (but lag behind them in positional understanding I suspect)

11. ....  f4 !!!! black is better    -1.53

oh yes, once the machine sees far enough, it LOVES 11... f4 - giving exactly StevanJovic's line too - exchange pawns, then when white captures with the knight, Bg5 pinning it in helplessly to the queen... a truly lovely tactic (and FAR beyond my level right now I think )

Yeah, that was my suggestion, offered in Post #33 above (without any engine confirmation, though).

If you mean 11. ... f4 12. gxf4 exf4 13. Nxf4 Bg5 that was me (Post #33)... but yeah, it looks strong for Black. In some lines, there's a Rook sac on f4 followed by Qf8.

fair enough - yes, sorry, it was the blueemu and it's an excellent line - great spot

... so you might be playing the Warthog again versus 1. c4 in the future?

Post the games if you do.

Just throw a King's Indian at them. Simple.

will do - although as I said at the start, I really don't see the English against me that often

@Manic, at the end, 41. .. h5 wins on the spot becaue white is in zugzwang, he cannot keep his only piece - his K - where it is, he has to move left or right, allowing your K entry in to his backyard for the win.  Your K will have unabated access to mop up his pawns while his K will have to be 2-3 steps behind.

A bit of study in endgames will .. maybe not Jeremy Silman's book, but spending some time in seeing how to win pawns games will finish off the fine start you had with the Dutch there.

If 11. .. f4 is your only hiccup for a new opening, you've done spectacular.  I relish those days I could make 8-10 moves without a mistake or blunder.

Thank you for your kind words - I think it is often difficult to judge how successful I've been with an opening as some games still do not make it into a middlegame at all at my level - so its easy to feel like the fact I didn't win a piece or end up with a checkmating attack means I did something wrong... but in fairness to my opponent I think he played rather well and found some surprising resources against me (Qa2+ was a huge surprise in the middle game and not a move I had considered at all, for example)