I feel like I'm consistently outplaying or at least staying even with other players my level through the middlegame, and am good at the "basic" endgames, but I've recently blown some games that I feel should have been at worst a draw for me.

First game - the careful approach:

 

I wouldn't want his rook behind my lines for the gain of a pawn, but to be honest I think you're fine after the following:

 

Just remember that if you're not a master player you're not expected to win all these supposed better positions. That's what defines master players. When you can finish off better positions consistently then you will be a master yourself.

Also, if you feel you have a grasp of the middlegame then just carry your knowledge there into your endgame. Most middlegame principles also apply to the endgame only with a slight difference.

(Disclaimer: I am not a master player, so take my analysis with a grain of salt.)

Thanks :). Yeah, there were certainly better lines that I missed. I could live with drawing that first position, but a loss from that starting position just seems unacceptable to me.

 

Anyone else?

Second game - Your plan should be obvious: get rid of his a2-pawn, which means targeting the b3-pawn without mercy - I would be willing to sacrifice quite heavily to get rid of the a2-pawn. Think of it like this: with the a2-pawn there it means there are seven mating squares b1, c1, d1, e1, f1, g1 and h1, which is like trying to defend against mate with another seven White kings on the board.

Something like the following, but it's a difficult position to defend for White.

 

Also, in the second game, the knight can take the pawn at b3.  (Ne2, Nc1, Nxb3)

As for the order of the moves.....hmm, devil's in the details, no.  lol  Just wanted to make you aware, if you weren't already.  :) 

yep, at first glance i was also thinking the knight could transition over to threaten b3 after the rook trade, and getting the d pawn out of the line of the bishop.  I'm probably missing some nasty tactics though.

It's usually good idea to have an extra pawn especially if it's a passed one so in the first game I would defifinitely favour 6... Rxb2. I would imagine black should win after that: it's unlikely that white can win d5 and even if he could it would take a lot of time which you can use to advance your passed pawn and your king is also more active than white's.

Of course after 6... Kf7 black hardly should loose. At move 7 you write: "I'm struggling to come up with any plan here. His rook is now much stronger than mine..." etc.  This suggests exchanging rooks as a possible plan. 7... Ra4 followed by Rb4 could be played. You start with more active king, good bishop and have fewer pawn islands so that the minor piece ending is probably quite good for you.

One could also dream about setup like h5+g5+Ra4/Rd1 then comes g5 followed by Rxd4. I don't know how realistic this is but maybe something like 6... h5 towards that goal could be considered.

After 9. Rb5 you could still pursue the e5 plan with something like 9... Ra7 followed by Rd7.

Well, these are just some ideas. Probably the main thing is just to come up with some sensible plan and carry it out agressively. In the game black seemed to drift without being able to decide a plan of action until his position became untenable.

By the way, interesting positions and good work on annotations which explain your thoughts very nicely.

Thanks :)

Heeeeeeeeeeeeeeeeee!!!!!!!

In the first game I agree that 5... Rxb2 was better for Black.  Still though, on the next move you could've won a pawn (6... Ra1+ followed by 7... Rf1).

Well,the second game is maybe losing for you.