[PokeCrystal] Did I do this shiny code correctly?

[AJayFalco]

Hello! I'm pretty new to this, and I altered the Crystal shiny odds using the unused check shininess as a guide. I thought I calculated this as being 1/606 shiny odds, but I think I messed something up. I'd greatly appreciate it if anyone has any pointers? Here's what I have for the 1/606 odds, if that's even correct;

INCLUDE "engine/gfx/sgb_layouts.asm"

DEF SHINY_ATK_DV EQU 10
DEF SHINY_DEF_DV EQU 10
DEF SHINY_SPD_DV EQU 10
DEF SHINY_SPC_DV EQU 10

CheckShininess:
; Return carry if the DVs at hl are all 10 or higher.

; Attack
    ld a, [hl]
    cp 13 << 4
    jr c, .not_shiny

; Defense
    ld a, [hli]
    and %1111
    cp 13
    jr c, .not_shiny

; Speed
    ld a, [hl]
    cp 12 << 4
    jr c, .not_shiny

; Special
    ld a, [hl]
    and %1111
    cp 13
    jr c, .not_shiny

; shiny
    scf
    ret

.not_shiny
    and a
    ret