A beginner's journal of little interest

[mitsun]

Perfect analysis, absolutely correct.
Now, how many points is (a) worth?

[Boidhre]

3 points for White I think. 1 point for Black. I suck at counting though.

[jts]

First rule of counting plays; it's always worth the same for both sides. Whatever b gains, w loses, and vice versa.

[Boidhre]

First rule of counting plays; it's always worth the same for both sides. Whatever b gains, w loses, and vice versa.

So 4 points then? Or am I estimating this all wrong?

[jts]

No, perfect, as far as I can tell. It's worth noting, though, that t3 is gote for w and t2 is sente for black; so it's as big as an 8 pt gote.

[Boidhre]

No, perfect, as far as I can tell. It's worth noting, though, that t3 is gote for w and t2 is sente for black; so it's as big as an 8 pt gote.

Where does that halving if it's gote rule come from? It's always confused me a little.

[jts]

Do you want an explanation or a demonstration?

[skydyr]

If you play a sente sequence, and get 4 points, then you get 4 points AND get to play the next biggest sequence, which you can assume generally to be near that in value. If you play gote, your opponent gets the next sequence, so if you play an 8 point gote and your opponent plays a 4 point sente, it's as if you played a 4-point sente, a 4-point gote, and it's then your opponent's turn.

Basically the gote is half as valuable because your opponent makes points back on his move, though half is an approximation.

At least that's my understanding of it, but I could be wrong.

Edit: This is very poorly explained. Please disregard it.

[Boidhre]

Do you want an explanation or a demonstration?

Just an explanation. I've just wondered about it being half because it assumes the next sequence after the gote sequence is of equal value which seems somewhat an inaccurate way to count something as vital as endgame moves. I'm hoping I'm very wrong here.

[jts]

No, you're right. The value of sente depends on the value of the next best move, so ending the game with a sente sequence, for example, is cold comfort. Double is a rule of thumb, based on the assumption that there are lots of endgame moves. The rule of thumb that modifies the rule of thumb is ".... But play the gote before reverse sente," which covers the cases where you can get the last gote before the board cools down by a point. If you need it more exact than that, you need to read out combinations and see which works best.

[Boidhre]

No, you're right. The value of sente depends on the value of the next best move, so ending the game with a sente sequence, for example, is cold comfort. Double is a rule of thumb, based on the assumption that there are lots of endgame moves. The rule of thumb that modifies the rule of thumb is ".... But play the gote before reverse sente," which covers the cases where you can get the last gote before the board cools down by a point. If you need it more exact than that, you need to read out combinations and see which works best.

Thanks jts. That answers my question perfectly. I guess at some point I'll get stuck into endgame theory but I feel and have been told, that right now the yose is the least of my worries.

[speedchase]

The Rule of thumb "play Gote before reverse sente" only applies if you halve the gote play, and not the reverse sente play when you count. To answer your earlier question, the above position is considered 4 points in miai counting, and it is not halved (because it is sente for one side and not the other).

[skydyr]

Do you want an explanation or a demonstration?

Just an explanation. I've just wondered about it being half because it assumes the next sequence after the gote sequence is of equal value which seems somewhat an inaccurate way to count something as vital as endgame moves. I'm hoping I'm very wrong here.

If the two moves are of exactly equal value and they are both gote, then they are miai and you can safely ignore them until your opponent plays one, when you take the other.

It is an abstraction, and breaks down in cases where the value of this gote (say 5) is more than the value of your opponents' sente (3) and the only other remaining play (1). Having just looked it up, though, it's because a gote move costs two plays (the first one and the last one, regardless of sequence), while a sente move costs 1 (since the opponent plays an equal number of times), so a gote move of 8 points / 2 stones played is the same as 4 points / 1 stone in sente.

[Boidhre]

Thanks skydyr and speedchase.

[Bill Spight]

No, perfect, as far as I can tell. It's worth noting, though, that t3 is gote for w and t2 is sente for black; so it's as big as an 8 pt gote.

Where does that halving if it's gote rule come from? It's always confused me a little.

First, T-02 is the right play for both players. If White plays at T-03, Black has a throw-in at T-02.

(;SZ[19]FF[4]AP[GOWrite:2.2.21]ST[2]CA[ISO8859-1]GM[1]AW[pq][qq][op][rr]GN[ ]PM[2]PW[ ]PB[ ]FG[259:]AB[qp][rp][rq][qm]
(
;B[sr]
;W[rs]C[*** 4 pt sente for black. Each player must make a protective play.]
)
(
;W[sr]C[*** 4 pt. reverse sente for White.]
;B[tt]
;W[sq]
;B[sp]C[*** Later White has this sente.]
)

(
;W[sq]C[*** Mistake.]
;B[sr]C[*** Black has this throw-in, for a 1/3 pt. loss for White.]
;W[tt]
;B[qr]
;W[ss]
;B[sp]
;W[pr]
;B[sr]
;W[qs]
;B[rs]
;W[qr]C[*** Later Black has this sente sequence, which is obviously better than the original sente.]
)

)

As for the halving rule, it is easy to explain. You have to realize that taking sente that belongs to you is like cashing a check. It gains nothing that you do not have a right to. It is the reverse sente that gains something. (By convention we say that the size of the sente is the size of the reverse sente. It actually gains more, but the reply takes that gain back.) For a gote, each player gains something. On average, each player gains the same amount. To calculate the average gain, you take half the difference between the result after Black plays gote and the result after White takes gote.

For instance, if a Black gote moves to a position worth 7 pts. for Black while the White gote in the same position moves to a position worth 1 pt. for Black, the value of the original position is 4 pts., and each player can gain 3 pts. in gote (which is half the difference between 7 and 1).

¿Es claro?