Rockman EXE . MegaMan Battle Network FAQ/Walkthrough

By Mega Boy

11. Busting Level

When you finish a battle, you will be given a rating. The better the rating, the better the Zenny or chance to get a Battle Chip.
Here's how you calculate your rating (1-lowest, 10-higher, S-Best)

Time:         The sooner you finish the battle, the higher the rating
    Normal enemies: <=5 seconds:        7 points
                    >5 ~ <=12 seconds:  6 points
                    >12 ~ <=36 seconds: 5 points
                    >36 seconds:        4 points
    Bosses:         <=30 seconds:       10 points
                    >30 ~ <=40 seconds: 8 points
                    >40 ~ <=50 seconds: 6 points
                    >50 seconds:        4 points

Damage:       The less your damage, the higher the rating
    0 hit:   1 point
    1 hit:   ±0 point
    2 hits:  -1 point
    3 hits:  -2 points
    4+ hits: -3 points

Movement:     The less you move, the higher the rating
    0~2 moves: 1 point
    3+ moves:  ±0 point

12. Chip Trader Machines

At Higsby's store, you will find two machines. If you put some Battle Chips of your choice, you can obtain another one, sometimes very rare!
As you can see, the type of chip you put as nothing to do with the one you get.

3-chips machine:
3/4 probability of having...
202/256 probability to get a 1-star chip
32/256 probability to get a 2-stars chip
16/256 probability to get a 3-stars chip
5/256 probability to get a 4-stars chip
1/256 probability to get a 5-stars chip

1/4 probability of having...
13/16 probability to get a 1-star chip
2/16 probability to get a 2-stars chip
1/16 probability to get a 3-stars chip

10-chips machine:
3/4 probability of having...
16/256 probability to get a 1-star chip
176/256 probability to get a 2-stars chip
32/256 probability to get a 3-stars chip
16/256 probability to get a 4-stars chip
16/256 probability to get a 5-stars chip

1/4 probability of having...
1/16 probability to get a 1-star chip
11/16 probability to get a 2-stars chip
2/16 probability to get a 3-stars chip
1/16 probability to get a 4-stars chip
1/16 probability to get a 5-stars chip