(;FF[4]GM[1]SZ[13]ST[2]CA[UTF-8]AP[SGFC:1.17]VW[]

GN[DoubleU-abel2011-663660-20110921]
PB[abel zapater (abel2011)]
BR[30k]
HA[5]
PW[W. Spencer Clark I (DoubleU)]
WR[18k]
KM[0.5]
DT[2011-07-16,2011-09-21]
PC[Dragon Go Server: http://www.dragongoserver.net/]
RE[W+56.5]
RU[Japanese]
GC[Game ID: 663660, rated]

AB[dd][jd][gg][dj][jj]PL[W];W[kc];B[ck];W[kk]LB[fk:A][jk:B]
C[Notice that W's strategy is to take the 3-3 point in every available 
corner.]
(;B[fk]LB[jk:A]MA[dj][ck]C[B's move is too passive because its only purpose is to strengthen 
the two marked stones, which are already safe (for now).

B needs to take initiative (sente) and apply pressure to W, either 
by threatening one of W's stones or threatening to make new territory 
somewhere.

For example, B could play at A.  W must respond immediately or 
lose the corner stone.  See variation.];W[cc]LB[dc:B][hk:A]
(;B[hk]LB[dc:X]C[Another mistake.  The bottom area is pretty secure for B, so 
this stone isn't doing any real work.  EVERY STONE YOU PLAY MUST 
WORK!  

B should put pressure on W's latest corner by playing at X. 

See variation.];W[ki];B[jl]LB[kj:X]C[B's move is largely wasted because B is already overconcentrated 
on the bottom.

As a general rule, you should cut your opponent in this situation 
by playing at X.  That would be a sente move (taking initiative) 
and W must respond.];W[kj]MA[jl]C[Now, because B did not cut W on the previous move, W simply connects. 
But this is a very strong move!  Not only does it secure W's 
corner, it also forces B to connect (as you correctly did).]
;B[jk];W[ji];B[ij]MA[ii]C[Another mistake.  B should play at X.  That would accomplish 
several things, including reducing W's liberties to push farther 
into the center and  giving him more potential territory on the 
right side.

The move you played is called an "empty triangle" and is considered 
"bad shape" because it is inefficient.  

For an explanation, see http://senseis.xmp.net/?TheEmptyTriangleIsBad

(By the way, this Sensei's Library website is one of the best 
go resources available -- very easy to look things up, see diagrams, 
get explanations, etc.)];W[ii];B[hi];W[ke];B[jb]LB[dc:B][jc:A]
[cd:C][jf:E][jg:D]MA[kd]C[B should have cut W at X  as in the previous discussion.

However, moves A, B, C and possibly D or E could also be considered.]
;W[kb];B[ic]C[Mistake!  B should make the solid connection (where W plays next).]
;W[jc];B[kd];W[ld];B[id];W[je];B[ie];W[jg];B[kg]MA[dc]C[Mistake:  B does not have enough space on the right side to live, 
so this invasion cannot possily succeed.  

It is better for B to play at X.  W will probably make a small 
corner territory but B will be ahead.];W[kf];B[lg]MA[dc]C[This is absolutely pointless for B; play at X.]
;W[lf];B[lh];W[li];B[mf];W[me];B[mg];W[kh];B[lc];W[lb]LB[if:B]
[jf:A]
(;B[jf]LB[if:X]SQ[jb][ic][id][jd][kd][ie]C[This is a mistake for B, as W can easily capture.  Also, you 
will see in the game that this capture ultimately allows W to 
extend into the center and (because B made overlooked other threats) 
eventually kill the marked stones.

It is much better for B to play at X (see variation).];W[if]
;B[mb]LB[hf:X]C[That is a mistake for B since there is no way any of those stones 
can possibly live.

What's important now is to play at X, blocking W from pushing 
farther into the center.];W[mc];B[kl];W[ll];B[ib];W[hf]LB[dc:X]
[cg:Y]C[Notice something interesting now:  W's last move lets him push 
into the center enough to tip the balance.  This is partly a 
result of B's ill-conceived invastion and B's move 38, which 
W captured.

B's situation is much more difficult now.  Playing at X is still 
urgent, but B also has to worry about a W invasion at Y.  There 
is no single move that can do both.];B[la];W[ka];B[ja];W[ma]
;B[ih];W[hh];B[hg];W[ig];B[gh];W[gf];B[ek]LB[gd:X][ef:Y]SQ[gf]
C[B is already overconcentrated on the bottom, so there is no reason 
to play here.

W's marked stone is very dangerous now.  If W can play at X, 
he will kill all B's stones in the upper right.

If B manages to play at X first, then W can simply extend to 
Y and make more trouble in the center and maybe even on the left 
side also.];W[ce]LB[cd:X][gd:Y]SQ[ja][ib][jb][ic][id][jd][kd]
[ie][gf]C[W has played a good extension.  In this case, because of W's 
marked stone, it is probably not safe for B to cut at X but better 
to defend at Y.

If W can  play at Y now it severely threatens B's 7 stones.]
;B[ee];W[cg];B[ff];W[gd]C[With this move B has lost.

Imagine the difference if B had played here on his previous move 
(or even on move 56)!

There is a go proverb I like very much:  "Opponent's next move 
is usually my best move."];B[fe]LB[fd:X]C[X is better because it defends B's stones here without making 
the empty triangle shape as you did.];W[hd];B[fg]LB[fd:Y][eg:X]
C[B's move is safe but not optimal or productive, because it fills 
a point of territory.  I would prefer X or Y.];W[fd]LB[cd:B]
[ed:A]
(;B[ed]LB[dc:X][cd:Z][de:Y]C[B did not have to connect here; you could afford to play somewhere 
else, like X.

Please notice that if W plays at 66, you can play at Y to connect 
(or vice-versa).  Two points like this are called "miai".  This 
is a useful concept to know about and you can find info on Sensei's 
Library.

The cut at Z is probably best (see variation).];W[cd]LB[eb:B]
[lm:A]
(;B[lm]MA[eb]C[Instead of this, consider X (variation).];W[lk]
;B[gi];W[ec];B[dc];W[fc];B[db];W[fa];B[gb];W[ea];B[ge]C[This is pointless for B, as the bamboo joint cannot be cut (http://senseis.xmp.net/?BambooJoint).

This move might be useful as a ko threat, but not here.];W[he]
;B[ga]C[Pointless.  B cannot save these stones.  It is better to play 
where W played next.];W[cb];B[gc]MA[ci]C[Again, pointless.  B could gain a point by playing where W played 
next.  

B should play at X.];W[da];B[hc];W[ha]C[Obviously urgent for W, since B could live by playing there.]
;B[fb];W[eb];B[ci];W[mh]C[W did not have to capture; B's stones were already dead.  In 
capturing, W merely filled one point of his own territory.]
;B[hj];W[de];B[dh]C[Good move.  W should have played here on his last move.]
;W[dg];B[eg];W[ml];B[eh]MA[bh]C[Not necessary to defend here.  X is a better move.]
;W[mm];B[km];W[ch];B[bh];W[bg];B[bi];W[ag];B[di]C[WHY??? 

B should play where W played next; that would save a point of 
territory.];W[ah];B[gk]LB[ia:A][ai:B]
(;W[ia]MA[ai]C[W is playing childlishly here, as B's stones are already dead. 
A better move is X (variation).];B[hb]MA[ai]C[B is wasting time and moves; his stones are dead.  Notice there 
is no possible way to make two eyes.

To play at X is important.];W[ha];B[df];W[cf];B[tt];W[ai];TW[aa]
[ba][ca][ga][ia][ja][la][ab][bb][fb][gb][hb][ib][jb][mb][ac]
[bc][gc][hc][ic][lc][ad][bd][id][jd][kd][md][ae][be][ie][le]
[af][bf][jf][mf][kg][lg][mg][lh][mi][lj][mj][mk]TB[fh][hh][ei]
[fi][ej][fj][gj]C[No further comment.])
(;W[ai];B[bj];W[aj];B[ak];W[df]C[This makes 2 more points for W.]
))
(;B[eb]LB[fb:B][ec:A]C[The other variation is a better move for W, but he may not see 
it.  Even so, this move give B some worthwhile counterplay.]
(;W[ec]C[This move looks OK at first but lets B live.];B[fc]
;W[dc];B[gc];W[hc];B[hb];W[gb];B[fb];W[db];B[ea];W[da];B[ga]
)
(;W[fb]C[W needs to play here];B[fc];W[gc];B[ec];W[gb];B[ba]
C[This move is called a "monkey jump".  

A proverb says, "the monkey jump is worth 10 points."];W[cb]
;B[ca];W[db];B[da];W[bb];B[ea];W[ab])))
(;B[cd];W[bd];B[dc];W[cb];B[db];W[fb];B[ca];W[ba];B[da];W[bb]
;B[dh];W[ch];B[ci];W[dg];B[eh];W[bi];B[bj];W[bh];B[eg];W[df]
;B[fa];W[gb];B[ga];W[ha];B[ea];W[hb];B[lm]C[This is a reasonable continuation.  B still loses, but not so 
badly.]))
(;B[if];W[ig];B[hg];W[dc];B[fd];W[fb];B[cd];W[bc];B[bd]C[Notice how solid B's stones are now.]
))
(;B[dc];W[cd];B[ce];W[be];B[cf];W[bf];B[cg];W[bg];B[bh];W[db]
;B[eb];W[cb];B[fc]C[Playing this way, W can have the corner but B is now much stronger 
in the center and on top.];W[jc];B[id];W[ic];B[hc];W[kd];B[ke]
;W[le];B[lf];W[ld];B[kg];W[kj];B[jk];W[kh];B[ji];W[ki];B[jh]
C[This is a reasonable continuation.  B is ahead.]))
(;B[jk];W[kj];B[ki];W[jl];B[il];W[kl]LB[kf:Y][gk:X]C[Now what happens?  If W is not careful, B can kill the corner. 
But W is the stronger player so he will probably live.  

Notice that even if W lives in the corner, B is stronger on the 
bottom and right side because of the stones he has played.  It 
will be difficult now for W to invade around X and Y.  

So this way of play is good for B.]))
