(;FF[4]GM[1]SZ[13]ST[0]AP[SGFC:1.13b]VW[]

GN[kyuless-Chevalier]
PB[Chevalier]
BR[28k]
HA[0]
PW[kyuless]
WR[27k]
KM[0.5]
DT[2003-01-18]

C[How could White have stopped Black's successful right side invasion?

Was Black able to more successfully invade White's territory...and if so, how?
(thanks!!)

z:
Game reviewed by Dimitri (12k* player "zenjutsu" on IGS).  I mark my comments with "z:", as above.  Please take every comment with a heavy dose of skepticism, as I am far from an expert in Go.  While I am not very familiar with 13x13 games, I will try to give the best commentary I am able.]
;B[dd];W[jj];B[dj];W[id]C[z:
While I'm not certain of 13x13 nuances, the 5-4 point seems too easy to invade.  In a 19x19 game, you might play such a point if your plan were to secure influence.  However, in 13x13, it seems that the board's size makes influence less key than territory in the corners and sides -- after all, there isn't much of a center to use that influence on.]
;B[fc];W[ig]C[z:
Again, the 5th line is for influence.  White does not yet own the right side, because black can easily invade with a stone on the third line.]
;B[dg]TR[cg]C[Black's side is becoming stronger.  However, last stone better on third line, I think.]
;W[gk]C[z:
Good.];B[fj]
(;W[gj]C[z:
Better if white plays F3 locally?  I'm not certain, but see alternative move tree.]
;B[fk];W[fl]C[z:
No!  Too small a play for this point in the game, _and_ it's gote.  Gote = loses initiative.]
;B[el];W[gl];B[he];W[ie];B[hd];W[hc];B[gc];W[ic]C[z:
White's side is still easily invadable.  Too high on 5th line. Also, I think this stone could safely by H12 (worth more... assuming white retains UR corner).]
;B[ge]TR[gg][hf]C[z:
?  Black did not need to play this stone.  If black truly feels a need to play locally, then triangles are better.]
;W[fi]TR[kd][cc]C[z:
Good idea -- increase your moyo while decreasing black's.  However, this move appears to be gote again.  Perhaps either a 3-3 invasion, or a reinforcement of your side?]
;B[ei];W[fh]TR[kc][ce]C[z:
This stone is why F6 was gote.  If black wanted, he could ignore this play, and go elsewhere.  Black decides to play locally, which is worth 5-10 points in middle territory, however black could have reinforced his upper left, or invaded white's right.]
;B[gg];W[gh];B[hg];W[hh];B[eg]C[z:
?  Wasted stone by black.  Completely unnecessary, and worth only one or two points in territory.  Black should have reinforced own UL corner, or attacked UR corner.]
;W[eh];B[dh];W[fg];B[ff];W[hf];B[gf]C[z:
Black should have let white capture his two stones.  It was only worth 6 points (white gains two prisoners, two territory points where the prisoners were, one point in not reinforcing J8, and black loses one point in having to reinforce F9).  On the other hand, reinforcing UL corner is worth about 10-20 points.  Attacking UR corner is also worth about 10-20 points.]
;W[if]C[z:
White should not reinforce here.  Same logic as black's last play.  If black captures white's H8 stone, then white can K8. Use this time to take the initiative with a 3-3 invasion (C11), or a reinforcement of your territory (L10).]
;B[kc]C[z:
Somebody _finally_ makes the move.  Too bad for W it was B who started it.]
;W[ke];B[kd]C[z:
?  Seems like an odd stone.];W[ld];B[lc];W[le];B[md]C[z:
?  This does nothing to make life.]
(;W[me]C[z:
No no no!  Black's last play was a HUGE goof, and it allowed white to kill corner.  Ask "could I reduce B's group to one eye?" If yes, then do so.]
;B[mc];W[jb]C[z:
Good!  B now dead.  Good job!];B[jc];W[kb]C[z:
Unnecessary.  Black was already dead (four square = one eye).]
;B[lb];W[ib]C[z:
Unnecessary.  If B tries to attack at J12, W just does H12 to put black in atari.]
;B[ki]C[z:
Interesting idea.]
(;W[jh]C[z:
No.  That joint does not need strengthening.  However, a stone at L4 would block B from the corner, thus ensuring his death.]
;B[kj];W[kk];B[ji];W[ij];B[lk];W[jk];B[li]C[z:
Now black looks very alive.];W[kl];B[ll];W[lm];B[mj];W[km];B[ml]
;W[mi]C[z:
?  This does nothing for white.  It just wastes a play, gives black a prisoner, and.... well, we'll just call it an "oops". Try to make certain to look at your play before placing it.  If you were black, how would you respond if white played there?]
;B[mh]C[z:
Easy choice for B.];W[lg];B[lh]C[z:
Unnecessary.  B is already alive.  M4 and N3 are two eyes for group.  Better play is at C9 to ensure entire left side and UL corner are secure from invasion.]
;W[kh];B[ii];W[ih];B[hi];W[gi];B[hj];W[hk];B[mg];W[kf];B[mf]
;W[lf];B[fm];W[gm]C[z:
All these last plays have been worth at most a few points each. An invasion / reinforcement of UL corner is still worth more points.]
;B[em];W[ek]C[z:
Good!];B[ej];W[dk]C[z:
Good follow through!];B[dl];W[ck];B[cl];W[cj];B[di];W[bl];B[bm]
;W[cm];B[bi];W[ci];B[ch]
(;W[dm]C[z:
Don't capture yet.  Not yet necessary.  You have two liberties to his one.  Play B4 first.]
;B[bg];W[cf];B[ce];W[gb];B[fb];W[fa];B[ea];W[ga];B[db];W[be]
C[z:
Interesting idea.  At your rank, it is good to experiment with invading your opponent.  However, be aware that you might "get away" with something that shouldn't work, so still do life-and-death problems to maintain "good habits".]
;B[bf];W[cd];B[de];W[cc];B[bd];W[dc];B[ec];W[cb];B[ae];W[ca]
;B[bc];W[ee];B[df];W[da];B[eb];W[ed];B[gd];W[ef]C[z:
FYI, that isn't a seki.  After white's C13 group is removed, B can safely play F9-10 and capture white's three stones.  So, basically white just gave B a point by giving a free prisoner.
...however, trying to make a seki is an excellent idea!  Generally, seki's in game are a higher-than-27k type of play.  It's good that you are experimenting.]
;B[bj];W[am]C[z:
?  Better at B3, if you wish to play locally.];B[bk];W[ak];B[aj]
;W[hb]C[z:
Unnecessary.  B couldn't attack it, so white just filled one of his own territory points.]
;B[al];W[fe]C[*Chevalier*: :-) ...

z:
Good.  It's good to practice playing out ko-threats.  I hear it helps make a player much stronger.  ...forces you to count the value of a play.]
;B[fd];W[ak];B[mm];W[al]C[*Chevalier*: I think it is over...

z:
I need to stress that this was a better game than I'd expect between a 27k and a 28k.  That shows that both players have great promise.  Keep up the good work!
However, for future improvement, I would _highly_ recommend life-and-death problems.  They will help you evaluate how to collapse an enemy's eyes, and thereby capture him.  They will also help you determine when your group is "unassailable" and does not need reinforcing. I feel this line of study would be very helpful for both white and black.  I sincerely appreciated the opportunity to review your game.

Thank you for the opportunity to review your game,
Dimitri ("zenjutsu")])
(;W[bj];B[aj];W[dm];B[ai];W[ak];B[bh]))
(;W[kj];B[ih];W[ii];B[jh];W[ji];B[kh]TR[lg][lj]C[z:
Black looks quite dead.  However, white could ensure black's demise with a triangle-marked play (for example).]
))
(;W[jb]C[z:
Black is now dead.]
(;B[me]C[z:
Black can "press the attack" (there really wasn't one to begin with -- the N10 stone was a waste)...]

(;W[mf]C[z:
...and W can block if they desire.];B[mc];W[kb];B[lf];W[lg]
;B[kf];W[je];B[kg];W[lh];B[kh];W[li];B[ki];W[kj];B[mg];W[lb]
;B[lj];W[lk];B[mj];W[mk];B[mh];W[mi];B[ih];W[ii];B[jh])
(;W[kb]C[z:
...and W can ignore if they desire.];B[lf];W[lg];B[kf];W[je]
;B[kg];W[lh];B[kh];W[li];B[ki];W[kj]))
(;B[kb]C[z:
If black tries to make eyes...];W[mb]C[z:
Then white plays to kill the eyespace.];B[me]C[z:
If black tries to "sneak out the bottom"...];W[mf]C[z:
...then white can block at his leisure.];B[mc];W[lf];B[la];W[ja]
;B[jc];W[ib];B[je];W[jf];B[ka];W[lb];B[ma]C[z:
Black has only one eye.  Dead.])))
(;W[fk];B[ek];W[gj]C[z:
I like this shape better for white than actual game.  But then I'm not certain it's better.]
))
