Sphinx v2.8 is a stone/imp which entered the Intel 88 hill in January 1993 and survived 2102 challenges before finally being pushed off in September.

;redcode quiet
;name Sphinx v2.8
;author W. Mintardjo
;strategy Stone/Spiral program with multi-pass core clear
;strategy Optimizing the constants. See how this one does
;assert CORESIZE==8000

IMP0    EQU IMP
IMP1    EQU IMP+2667
IMP2    EQU IMP+2667+2667

Init    EQU Wait+2584

launch  MOV Stone+4, Init-0
        MOV Stone+3, Init-1
        MOV Stone+2, Init-2
        MOV Stone+1, Init-3
        MOV Stone+0, Init-4
        MOV Stomp+0, Init-5

        SPL Init-5, <7115
        SPL Init-5, <6304
        SPL Init-5, <5303
        SPL Init-5, <5902
        SPL Init-5, <4061

        SPL 16, <3708
        SPL 8, <1935
        SPL 4, <1814
        SPL 2, <2011
        JMP IMP0, <7370
        JMP IMP1, <6013
        SPL 2, <5812
        JMP IMP2, <4811
        JMP IMP0+1, <3910
        SPL 4, <7517
        SPL 2, <4916
        JMP IMP1+1, <2215
        JMP IMP2+1, <7214
        SPL 2, <7013
        JMP IMP0+2, <6712
        JMP IMP1+2, <6511
        SPL 8, <6110
        SPL 4, <5617
        SPL 2, <5216
        JMP IMP2+2, <3511
        JMP IMP0+3, <1910
        SPL 2, <2417
        JMP IMP1+3, <3316
        JMP IMP2+3, <4603
        SPL 4, <3602
        SPL 2, <4161
        JMP IMP0+4, <3104
        JMP IMP1+4, <2903
        SPL 2, <2172
        JMP IMP2+4, <1517
        JMP IMP0+5, <1011

Stone   MOV <4+2584+2584, -2584-2584
        SUB 3, -1
        DJN -2, #886
        MOV 1, -2
        JMP -2584, 2584

        DAT #0
        DAT #0
        DAT #0
        DAT #-2200

        DAT #0
        DAT #0

        DAT <-4, <-5
Stomp   SPL 0, <-3
        MOV -2, <-4
        JMP -1, <-5

Wait    SLT #-3195, @Stomp+1
        MOV #-6, @Stomp+1
        JMP -2, <-8

IMP     MOV 0, 2667