1RB1LA------_1RC3LB1RB---_2LA2LC---0LC

1RB1LA------_1RC3LB1RB---_2LA2LC---0LC (bbch) is the current BBi(8) champion. It runs for over $10^{1565}$ steps and has a sigma score of exactly ${\frac {3^{1642}-11}{2}}$. It was discovered by Nick Drozd on 26 July 2025 (Discord link).

Analysis by Shawn Ligocki

A(a, b, c) = <A 2^a 0 3^b 1^c 2

A(a, b+1, c) -> A(a+3, b, c)
A(a, b, c) -> A(a+3b, 0, c)

A(a, 0, c+2) -> A(2, a+5, c) - > A(3a+17, 0, c)
A(a, 0, 2k+r) -> A(((2a+17) 3^k - 17)/2, 0, r)

A(a, 0, 1) -> A(2, 1, a+6)
A(a, 0, 0) -> Halt(a+3)

Start: A(2, 1, 1) @12

A(2, 1, 2k+1) -> A(2, 1, (3^{k+3} - 5)/2)
A(2, 1, 2k) -> Halt((3^{k+3} - 11)/2)

and the trajectory (just looking at c values) is:

c0 = 1
c1 = (-5 + 3^3)/2 = 11
c2 = (-5 + 3^8)/2 = 3278
Halt((-11 + 3^1642)/2)

The final score can also be written as

$${\frac {-11+3^{\frac {7+3^{\frac {5+3^{3}}{4}}}{4}}}{2}}$$