So How Did I Get That Rating?
BAL ratings are calculated after each round.
 Games won by forfeit are not counted for rating purposes.
 For rating purposes, new, unrated players are assumed to have an initial rating of 1300 based on zero previous games.
Within a rating cycle, performance ratings are first calculated for all new, unrated players. These performance ratings are then used when calculating the ratings of the remaining players.
Provisional Ratings Calculation
The provisional rating calculation formula is:(n_{p} × R_{p}) + ( ∑ R_{o }) + (400 × ( ∑ W  ∑ L)) 

G = 
n_{p} + n_{c} 
 R_{p} 
where
G is
the gain in rating (can be negative),
n_{p}
is the number of games
played prior to the ratings cycle,
R_{p} is the player's previous rating,
∑ R_{o }is the sum of the ratings of the player's opponents,
∑ W is the sum of the player's wins (win = 1, draw = 0.5),
∑ L is the sum of the player's losses (loss = 1, draw = 0.5), and
n_{c }is the number of games played in this ratings cycle
R_{p} is the player's previous rating,
∑ R_{o }is the sum of the ratings of the player's opponents,
∑ W is the sum of the player's wins (win = 1, draw = 0.5),
∑ L is the sum of the player's losses (loss = 1, draw = 0.5), and
n_{c }is the number of games played in this ratings cycle
Established Ratings Calculation
The established rating calculation is a bit more complex:G =  k × ( ∑W  ∑W_{e }) 
where
G
is the gain in rating (can be negative),
k is a constant based on the player's previous rating (16 if over 2399, 24 if between 2100 and 2399, and 32 otherwise),
∑W is the sum of the player's game scores (win = 1, loss = 0, draw = 0.5), and
∑W_{e} is the sum of the player's "expected wins" against each opponent, computed for each opponent as:
k is a constant based on the player's previous rating (16 if over 2399, 24 if between 2100 and 2399, and 32 otherwise),
∑W is the sum of the player's game scores (win = 1, loss = 0, draw = 0.5), and
∑W_{e} is the sum of the player's "expected wins" against each opponent, computed for each opponent as:
1 

W_{e} = 
1 + 10 ^{ (Δr ÷ 400)} 
where Δr is the difference
between the
player's and opponent's rating.
KAdjustment
After the appropriate calculation is performed, the resulting gain may be adjusted if the player's new rating crosses one of the "k" boundaries as follows ( RO = old rating, RN= new rating):If (either RO or RN) > 2099
If
((both RO and RN) ≥ 2400) OR (2100 ≤ (both RO and RN) ≤ 2400)
ElseRN
is not changed
ElseIf (RO <
2100)RN
= 2100 + (RN  2100) × 0.75
ElseIf RO <
2400If
RN < 2100
ElseIf RO ≥ 2400RN
= 2100 + (RN  2100) × 1.33
ElseIf RN >
2399RN
= 2400 + (RN  2400) × 0.66
ElseRN
is not changed
If
RN < 2400
RN = 2400 + (RN  2400) ×
1.50
ElseRN
is not changed
RN
is not changed