If White has a sente, he will play 1 to 7.

[SuprunP]

$$W If White has a sente, he will play 1 to 7.
$$ ------------------
$$ . . . . . . . . .|
$$ . . 6 4 2 . . . .|
$$ . 7 5 3 1 X X . .|
$$ . . . . . O O . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|

Click Here To Show Diagram Code

[go]$$W If White has a sente, he will play 1 to 7.
$$ ------------------
$$ . . . . . . . . .|
$$ . . 6 4 2 . . . .|
$$ . 7 5 3 1 X X . .|
$$ . . . . . O O . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|[/go]

"Black can crawl on the second line - the line of defeat - all he wants, and White will answer him gladly at every step.
(Toshiro Kageyama; Lessons in the Fundamentals of Go)

Unfortunately the author does not go on explaining why exactly White is happy to have Black on the second line in this situation and I feel like he might have expanded on this fundamental principle a little bit more...

Would you be so kind to shed some light on it?

Thanks.

[ilFuria]

I'm guessing that black gains ~1 point per move while white thickness towards the centre is much more valuable.

[Bill Spight]

$$W If White has a sente, he will play 1 to 7.
$$ ------------------
$$ . . . . . . . . .|
$$ . . 6 4 2 . . . .|
$$ . 7 5 3 1 X X . .|
$$ . . . . . O O . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|

Click Here To Show Diagram Code

[go]$$W If White has a sente, he will play 1 to 7.
$$ ------------------
$$ . . . . . . . . .|
$$ . . 6 4 2 . . . .|
$$ . 7 5 3 1 X X . .|
$$ . . . . . O O . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|
$$ . . . . . . . . .|[/go]

On an empty board, is bad. As ilFuria points out, it gains only 1 point or so along the side, while gains more than that in the center. How much more is unclear, but the consensus is that it gains more than 2 points. IMO, and in the opinion of many others, it gains more than 3 points.

(;CA[ISO8859-1]AP[GOWrite:2.2.21]GM[1]ST[2]FF[4]SZ[19]FG[259:]AW[ac][bc][cc][dc][ec][fc][gc][hc][ic][jc][kc][lc][mc][nc][oc][pc][qc][rc][sc]PM[2]AB[ad][bd][cd][dd][ed][fd][gd][hd][id][jd][kd][ld][md][nd][od][pd][qd][rd][sd]PW[ ]GN[ ]PB[ ]
)

IMO, this position is worth around 25 points for Black, somewhat less than a 2 stone handicap.