Bill Spight wrote:Playing a local sente with sente gains nothing, in terms of points.
For those who are confused about this detail - have you ever noticed that when pros or top amateurs estimate the score, they always pre-subtract out the sente pushes and other sente intrusions, even if the opponent hasn't played them yet? (See any number of online Go commentary videos, or if you've been to a Go club or Congress you may have seen strong dan players or pros do this in-person). Pretty much every strong amateur or pro that I've ever encountered counts this way.
That's because a very good "baseline" is that whenever a player has a clear sente move, they assume for estimation purposes that player will get it. So when that player actually does play that move in sente, there is no gain. Relative to that baseline, they have only gotten exactly what they already counted that player to get!
That's basically what "sente gains nothing" means.
Pio2001 wrote:Even today, I feel confused, even about the modern "miai values". For example, when I compare a sente move with a value of 1 point and a gote one with a value of 20 points.
If I apply the traditional rule that says that a sente move is worth twice a gote move, and even if I use the modern "tally" calculation, all the theory says that the gote move is worth much more that the sente move, while it is obvious to anyone that it is better to play the sente first, in order to get both.
The simple answer is that you might be mistaken about what "modern" counting theory says

. There are TWO important values for locally-sente moves, not one - the reverse sente value (also known as the miai value, or the per-move gain), and the threat value - the
gain of the followup move if unanswered.
So let's say in your example the local-sente move has a reverse-sente value of 1 point and a threat value of 7 points. In that case, modern theory says to play it any time when the biggest moves elsewhere on the board are worth between 1 and 7 points. Ideally as late as possible to preserve ko threats, but definitely don't let it sit until moves elsewhere are all worth less than 1 point, then the opponent will be able to take it and you will lose out.
If you played it while there was a 20 point gote on the board, that would be a huge mistake, since the opponent would ignore it and take the 20 point gote. If on the other hand, the threat value was 30 points, then you could certainly play it now if you didn't mind using up the ko threat - in that case, theory would say to play it any time when moves elsewhere are worth between 1 and 30 points instead of 1 and 7 points. But you could also still wait, so long as there would still be other moves worth between 1 and 30 points after the 20-point gote was gone.
Does that make sense? (This is basically what Bill said, but restated in case a different way of wording it helps it stick).