PGN Enhancement

[calcitem]

1. d6 f4 {Both sides attempt to control the crossroads in the opening}
    (1... c4? {If Black tries to occupy the inner ring}
        2. d2 b4 {White can immediately seize another crossroads, gaining the initiative}
        2... f4 {Black chooses to occupy another crossroads, but this gives White the opportunity to control three crossroads in total})
2. d2 b4 {Both sides each seize two crossroads}
3. g4 d7 {White's move to g4 aims to block Black; Black develops d7 in response to White’s possible expansion}
4. a4 d1 
    (4... c5? {If Black moves to c5, it has little impact}
        5. d1 {White can quickly break through})
5. d5 d3 {White's d5 move strengthens control of the inner ring; Black’s d3 also advances towards the inner ring}
6. e4 f6
7. f2 b2
8. b6 g7
9. a7 c3
10. d5-c5 c3-c4 {Black is unable to prevent White from forming a mill at c5-d5-e5}
    (10... d3-e3 {Another approach is to play d3-e3, but it cannot stop White from forming a mill})
11. e4-e5 d1-a1 {White moves e4-e5, making the formation of a mill inevitable; Black is helpless}
12. d6-d5xd7 f4-e4 {White captures one of Black’s pieces, while Black also attempts to form a mill}

[calcitem]

1. d6 f4 {Both sides attempt to control the crossroads in the opening}
2. d2 b4 {Both sides each seize two crossroads}
3. g4 {White's move to g4 aims to block Black} d7 {Black develops d7 in response to White’s possible expansion}
4. a4 d1 
5. d5 d3 {White's d5 move strengthens control of the inner ring; Black’s d3 also advances towards the inner ring}
6. e4 f6
7. f2 b2
8. b6 g7
9. a7 c3
10. d5-c5 c3-c4 {Black is unable to prevent White from forming a mill at c5-d5-e5}
11. e4-e5 d1-a1 {White moves e4-e5, making the formation of a mill inevitable; Black is helpless}
12. d6-d5xd7 {White captures one of Black’s pieces} f4-e4 {while Black also attempts to form a mill}

Not support:

1. d6 f4 {Both sides attempt to control the crossroads in the opening}
2. d2 b4 {Both sides each seize two crossroads}
3. g4 {White's move to g4 aims to block Black} d7 {Black develops d7 in response to White’s possible expansion}
4. a4 d1 
5. d5 d3 {White's d5 move strengthens control of the inner ring; Black’s d3 also advances towards the inner ring}
6. e4 f6
7. f2 b2
8. b6 g7
9. a7 c3
10. d5-c5 c3-c4 {Black is unable to prevent White from forming a mill at c5-d5-e5}
11. e4-e5 d1-a1 {White moves e4-e5, making the formation of a mill inevitable; Black is helpless}
12. d6-d5 {White forms a mill} xd7 {White captures one of Black’s pieces} f4-e4 {while Black also attempts to form a mill}

[calcitem]

1. d6 {good!} f4
2. d2 b4
3. g4 d7
4. a4 d1 
5. d5? d3
6. e4 f6!!
7. f2 b2
8. b6 g7??
9. a7 c3!
10. d5-c5 c3-c4
11. e4-e5 d1-a1
12. d6-d5xd7 f4-e4
1/2-1/2

[calcitem]

1. D6 f4 {Both sides attempt to control the crossroads in the opening}
    (1... c4? {If Black tries to occupy the inner ring}
        2. d2 b4 {White can immediately seize another crossroads, gaining the initiative}
        2... f4 {Black chooses to occupy another crossroads, but this gives White the opportunity to control three crossroads in total})
2. Whited2 b4 {Both sides each seize two crossroads}
3. g4 d7 {White's move to g4 aims to block Black; Black develops d7 in response to White’s possible expansion}
4. a4 d1 
    (4... c5? {If Black moves to c5, it has little impact}
        5. d1 {White can quickly break through})
5. d5 d3 {White's d5 move strengthens control of the inner ring; Black’s d3 also advances towards the inner ring}
6. e4 f6
7. f2 b2
8. b6 g7
9. a7 c3
10. d5-c5 c3-c4 {Black is unable to prevent White from forming a mill at c5-d5-e5}
    (10... d3-e3 {Another approach is to play d3-e3, but it cannot stop White from forming a mill})
11. e4-e5 d1-a1 {White moves e4-e5, making the formation of a mill inevitable; Black is helpless}
12. d6-d5xd7 f4-e4 {White captures one of Black’s pieces, while Black also attempts to form a mill}

[calcitem]

1. d6 f4 {Both sides attempt to control the crossroads in the opening}     (1... c4? {If   tries to occupy the inner ring}         2. d2 b4 {  can immediately seize another crossroads, gaining the initiative}         2... f4 {  chooses to occupy another crossroads, but this gives   the opportunity to control three crossroads in total}) 2. d2 b4 {Both sides each seize two crossroads} 3. g4 d7 { 's move to g4 aims to block  ;   develops d7 in response to  ’s possible expansion} 4. a4 d1      (4... c5? {If   moves to c5, it has little impact}         5. d1 {  can quickly break through}) 5. d5 d3 { 's d5 move strengthens control of the inner ring;  ’s d3 also advances towards the inner ring} 6. e4 f6 7. f2 b2 8. b6 g7 9. a7 c3 10. d5-c5 c3-c4 {  is unable to prevent   from forming a mill at c5-d5-e5}     (10... d3-e3 {Another approach is to play d3-e3, but it cannot stop   from forming a mill}) 11. e4-e5 d1-a1 {  moves e4-e5, making the formation of a mill inevitable;   is helpless} 12. d6-d5xd7 f4-e4 {  captures one of  ’s pieces, while   also attempts to form a mill}

[calcitem]

[FEN "********/O*O*@*@*/******** w p p 2 7 2 7 0 0 0 0 0 0 0 0 1"]
[SetUp "1"]

 1.    d1    f6
 2.    a4