dhu163's comments are pretty-much spot on. With
admittedly, I wasn't really thinking about L&D when I made the comment, and usually it is bad endgame to play the descent as was mentioned.
As for the numbers, there are only emojis for 1-99 and 00 for each colour. After that you're on your own.
Regarding the game against CoSting, at
once you cut black's corner group is basically alive already, so there's no wiggle room there. Black's center stones have good access to the center, and are not short of liberties, so there's not a lot white can do their either. That only leaves the other side, but black can play there immediately, since the cut is not a big threat.
The other issue for more general situations is that when you invade, you take away territory, but you give influence in exchange. That is, by living inside, your opponent generally gets a wall oun the outside. Influence is most valuable early in the game, since it affects empty areas and those fill up as the game goes on. Later on, it becomes less and less valuable, because the areas it can influence become smaller and smaller as each sides stones become stronger through normal play. Invasions ideally occur immediately before your opponent would want to consolidate the territory. Too early, and the resulting wall would be too valuable, or (for consolidation) making territory would be too slow. Too late, and your opponent takes it first.
As a second thing to consider, when you're invading, you generally want to have 3 good followups, so that you don't come under too much pressure. And finally, it's also worth considering whether you should invade (which often ends in gote) or reduce from the outside (often ends in sente). This ties in to counting as well, since you need to know how much you need to ruin to win.
For
, I think black could just play one space farther away, instead of a contact move. I thought I put that in, but maybe not.
For
, it's poor shape because black is peeping at cutting the keima, and this move lets him cut it. Without really looking back at the game to read it, the standard idea would be some sort of move that keeps black split and white connected. Cutting your opponent and staying connected yourself are very basic principles to play by. I suspect you expected your opponent to extend towards his other stone, but you always need to look for ways your opponent can fight back.
At 119, it seems obvious to me, at least, that black's lower left is going to live. You can draw a line between the outermost stones of white's formation to get an idea of the territory it encompasses, say from E8 to M9. Without actually counting, but just roughly comparing territories, this area isn't much bigger than black's upper left. However, black also has the UR corner, the LR corner, and something that looks decently sized in the lower left, plus potential to make a lot of points with a simple extension along the bottom.
For 138, this is the result of a few thoughts:
First, white's group isn't in any danger of dying or being cut, so playing here only prevents a sente peep.
Second, white's group on the other side is strong too, so if black plays on this side, white can reduce from the other side.
Third, black's group is alive and also has good access to the side.
You may have heard the proverb to play away from thickness, and there's nothing thicker than unconditionally alive. Because each side has strong reinforcements here for any fighting, it's easy for each side to prevent the other from making a lot of points. Generally, you can consider that the end result will be kind of a wash, with neither side gaining over the other much. Because of that, I feel playing in a less developed area would be a lot bigger, without actually counting it.
For 140, that's a good question. There's something to be said for using that stone's aji, since it's already dead. My concern is that black could play, say, an attachment at H4 and then in the fight kill the aji and get stronger in the center. Then after the fight is done, black can still reduce from the right, and black is strong in the center so he can reduce white's center a lot. It's also possible that black might move into the center right away, betting that he can live and hurt white more than white hurts black. That said, white's behind right now, so maybe it's better to play your way and make things more confusing for black. Also, if white plays too high, black can just make points on the bottom to counter the additional points that white is getting in the center. I guess it's really a question of 'how do I hope or think black will screw up?' given that white is pretty far behind at this point.
or 
: Black can play and create at least a ko for life/death (how?). Also at 
black can play a better move and kill white (imho). I would recommend to have a close look on the whole sequence starting with 
. 
was extremely strange and critical mistake, looks like you didn't notice atari
see better move
see better move
Thank you, I couldn't see that the cut was not a threat.
In the variation, why is this a bad shape? (see diagram)
What do you mean this is a overplay? What would the normal play be?
:b101:
In your var, please see ElephantsEye.
Maybe this var:
It's big for W to connect his weak group (you let him);
F3 direction (approach) is good.
P2.
Not small, but gote. You should tenuki.
Bad habit. Forcing your opponent to make good shape, to live, (to get a good result for him) without a very good reason is bad. For one thing, you just waste at least one ko threat.
atari at M1 is bad -- just pull back at M2.
R15.