|
1. When 2 groups without eyes can't connect
with friendly stones and are forced to fight each-other for survival, the
position is called SEMEAI (in Japanese). In the folowing diagrams is black to
play. Before going to the next one please try to figure out who's winning the
clash. |
|
2. As seen here, black wins. He had 4
liberties to white 4 but first to move, so it's easy to guess that this was
the main reason for his success. |
|
3. How about this semeai? Black has 3
liberties to white's 4... Can black win such a fight? |
|
4. The trick is that white's group involved
in fight is going nowhere... so black can extend his number of liberties to 5
by playing at 1! Even if white plays at 2, black can start the fight with 3.
After this move, black has 4 liberties to white's 3. |
|
5. Starting at 1 as seen here is not
helping... Black is losing the fight by one liberty... |
|
6. This time we have 2 groups with 4
liberties each. Black to move and win the fight. |
 |
7. This move blocks white's expansion so the
fight is decided now:black's 4 liberties to white's 3, so black wins.
|
|
8. You must be very careful at the order of
the moves! Black 1 here was careless and white 2 makes it impossoible for
black to win. After white 4, black is down to 2 liberties against white's 3.
|
|
9. This time we have 2 groups with 4
liberties each but the one at A is common. Black can win but how?
|
|
10. This is the correct order! By playing
this way black keeps the advantage of playing first. Eventually he will
capture white. |
|
11. Playing this way is a fatal error! After
black 1, the situation is 3 to 3 but white to move! Please see how black is
losing the fight... As a general rule, the common liberties should be played
last! |
|
12. How about this shape? Black has 4
liberties to white's 4. Can he win the fight? Please notice the 2 common
liberties! |
 |
13. Black should start from exterior, but
after white 4 both players are left without any posibility to move. If either
A or B is played by one player, the other will just capture the entire group.
This is a SEKI (both alive). |
 |
14. This time black is having 8 liberties to
white 6. Blakc to move. |
|
15. Even if playing first and having 2 more
liberties, the black group can't win the semeai. The reason? The large number
of common liberties. |
|
16. Black 5 against white 4. Who wins?
|
 |
17. Black can't avoid the capture... The
reason this time was the 2 common liberties and the eye white is having as a
liberty that should be taken last! (suicide is forbidden) |
 |
18. Let's see another example with one eye
for white. This time one common liberty and one eye for white, but black is
having 5 liberties to white 4! |
 |
19. Black can win the fight! Those examples
showed us that not only the total number of liberties is important, but also
if there is an eye or not and the number of common liberties. Let's see some
more examples! |
|
20. Here we have 2 groups with one eye each,
one common liberty and 3 external liberties. |
|
21. After playing out all the external
liberties, the position ends up as a SEKI (both groups alive). |
|
22. This time a more difficult problem.
Black is having a big eye (he can capture 3 stones and gets 3 liberties by
doing so) but only one external liberty. Who wins this fight? |
|
23. Although a little bit complicated, the
big eye black proves useful and here is the best sequence for both. |
|
24. As a conclusion, although white has 3
distinct liberties to black's 2, when white plays C he will be left with only
2 liberties while black, forced to capture at B, will have 3 liberties! In
this case, white is considered dead, being unnecessary for black to capture
white (he can do it by starting at A, white is paralized, so black continues
at B, getting into a 3 to 2 position which he can easily win). |
|
25. Here black has 7 liberties to white's 9,
but he can still win... How? |
 |
26. Making an eye is enough to guarantee
success, as shown here. |
|
27. Trying to fight on liberties is failing.
Please figure out the rest of the sequence by yourself. |